Document and Entity Information Document - USD ($)	12 Months Ended
Document and Entity Information Document - USD ($)	Dec. 31, 2015	Feb. 12, 2016	Jul. 01, 2015
DEI [Abstract]
Entity Registrant Name	INTERPUBLIC GROUP OF COMPANIES, INC.
Entity Central Index Key	0000051644
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	1215
Document Fiscal Period Focus	FY
Amendment Flag	false
Trading Symbol	IPG
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		402,129,565
Entity Public Float			$ 7,929,404,708

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
REVENUE	$ 7,613.8	$ 7,537.1	$ 7,122.3
OPERATING EXPENSES:
Salaries and related expenses	4,857.7	4,820.4	4,545.5
Office and general expenses	1,885.0	1,928.1	1,917.9
Restructuring and other reorganization-related (reversals) charges, net	(0.8)	0.2	60.6
Total operating expenses	6,741.9	6,748.7	6,524.0
OPERATING INCOME	871.9	788.4	598.3
EXPENSES AND OTHER INCOME:
Interest expense	(85.8)	(84.9)	(122.7)
Interest income	22.8	27.4	24.7
Other expense, net	(46.7)	(10.2)	(32.3)
Total (expenses) and other income	(109.7)	(67.7)	(130.3)
Income before income taxes	762.2	720.7	468.0
Provision for income taxes	282.8	216.5	181.2
Income of consolidated companies	479.4	504.2	286.8
Equity in net income of unconsolidated affiliates	1.1	1.2	2.1
NET INCOME	480.5	505.4	288.9
Net income attributable to noncontrolling interests	(25.9)	(28.3)	(21.0)
NET INCOME ATTRIBUTABLE TO IPG	454.6	477.1	267.9
Dividends on preferred stock	0.0	0.0	(8.7)
NET INCOME AVAILABLE TO IPG COMMON STOCKHOLDERS	$ 454.6	$ 477.1	$ 259.2
Earnings per share available to IPG common stockholders:
Basic	$ 1.11	$ 1.14	$ 0.62
Diluted	$ 1.09	$ 1.12	$ 0.61
Weighted-average number of common shares outstanding:
Basic	408.1	419.2	421.1
Diluted	415.7	425.4	429.6
Dividends declared per common share	$ 0.48	$ 0.38	$ 0.30

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 480.5	$ 505.4	$ 288.9
Other Comprehensive Income
Foreign currency translation adjustments	(256.8)	(194.3)	(116.9)
Less: reclassification adjustments recognized in net income	23.3	(0.9)	0.0
Income tax effect	0.0	0.0	(0.6)
Foreign currency translation, net of tax	(233.5)	(195.2)	(117.5)
Available-for-sale securities:
Changes in fair value of available-for-sale securities	0.5	0.7	0.8
Less: recognition of previously unrealized (gains) losses included in net income	0.0	0.0	(1.4)
Income tax effect	0.0	(0.3)	0.2
Available-for-sale securities, net of tax	0.5	0.4	(0.4)
Derivatives instruments:
Changes in fair value of derivative instruments	0.0	(0.6)	0.0
Less: recognition of previously unrealized losses included in net income	2.0	1.9	1.7
Income tax effect	(0.7)	(0.5)	(0.7)
Derivative instruments, net of tax	1.3	0.8	1.0
Defined benefit pension and other postretirement plans:
Net actuarial gains (losses) for the period	14.2	(55.5)	(20.6)
Less: amortization of unrecognized losses, transition obligation and prior service cost included in net income	10.6	10.0	10.8
Less: settlement and curtailment (gains) losses included in net income	(0.2)	0.5	(0.1)
Other	0.4	0.5	1.0
Income tax effect	(6.4)	10.4	(1.3)
Defined benefit pension and other postretirement plans, net of tax	18.6	(34.1)	(10.2)
Other comprehensive loss, net of tax	(213.1)	(228.1)	(127.1)
Total comprehensive income	267.4	277.3	161.8
Less: comprehensive income attributable to noncontrolling interest	21.7	25.7	17.1
Comprehensive Income Attributable to IPG	$ 245.7	$ 251.6	$ 144.7

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
ASSETS:
Cash and cash equivalents	$ 1,502.9	$ 1,660.6
Marketable securities	6.8	6.6
Accounts receivable, net of allowance of $54.2 and $59.5	4,361.0	4,376.6
Expenditures billable to clients	1,594.4	1,424.2
Other current assets	228.0	342.2
Total current assets	7,693.1	7,810.2
Property and equipment, net	567.2	548.2
Deferred income taxes	228.4	192.9
Goodwill	3,608.5	3,669.2
Other non-current assets	487.9	516.1
TOTAL ASSETS	12,585.1	12,736.6
LIABILITIES:
Accounts payable	6,672.0	6,558.0
Accrued liabilities	760.3	796.0
Short-term borrowings	150.1	107.2
Current portion of long-term debt	1.9	2.1
Total current liabilities	7,584.3	7,463.3
Long-term debt	1,610.3	1,612.9
Deferred compensation	464.2	527.9
Other non-current liabilities	672.6	723.9
TOTAL LIABILITIES	$ 10,331.4	$ 10,328.0
Commitments and contingencies (see Note 14)
Redeemable noncontrolling interests (see Note 4)	$ 251.9	$ 257.4
STOCKHOLDERS' EQUITY:
Common stock, $0.10 par value, shares authorized: 800.0 shares issued: 2015 – 406.3; 2014 – 414.6 shares outstanding: 2015 – 403.2; 2014 – 413.8	40.4	41.2
Additional paid-in capital	1,404.1	1,547.5
Retained earnings	1,437.6	1,183.3
Accumulated other comprehensive loss, net of tax	(845.6)	(636.7)
Stockholders Equity Subtotal Before Treasury Stock	2,036.5	2,135.3
Less: Treasury stock, at cost: 2015 - 3.1 shares; 2014 - 0.8 shares	(71.0)	(19.0)
Total IPG stockholders' equity	1,965.5	2,116.3
Noncontrolling interests	36.3	34.9
TOTAL STOCKHOLDERS' EQUITY	2,001.8	2,151.2
TOTAL LIABILITIES AND EQUITY	$ 12,585.1	$ 12,736.6

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 54.2	$ 59.5
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	800.0	800.0
Common stock, shares issued	406.3	414.6
Common stock, shares outstanding	403.2	413.8
Treasury stock, shares	3.1	0.8

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 480.5	$ 505.4	$ 288.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of fixed assets and intangible assets	157.0	163.0	157.4
Provision for uncollectible receivables	11.4	7.4	12.6
Amortization of restricted stock and other non-cash compensation	70.3	54.3	43.1
Net amortization of bond discounts and deferred financing costs	5.8	5.1	8.6
Non-cash Gain (Loss) on Extinguishment of Debt	0.0	0.5	(15.2)
Deferred income tax provision	49.5	83.5	69.4
Losses on sales of businesses	50.1	0.2	1.0
Other	23.6	12.8	2.2
Changes in assets and liabilities, net of acquisitions and dispositions, providing cash:
Accounts receivable	(236.1)	(20.1)	(157.1)
Expenditures billable to clients	(237.8)	83.5	(241.5)
Other current assets	(9.2)	(57.2)	(11.3)
Accounts payable	400.9	(177.1)	417.7
Accrued liabilities	(35.3)	39.8	(17.4)
Other non-current assets and liabilities	(56.7)	(30.6)	4.1
Net cash provided by operating activities	674.0	669.5	592.9
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(161.1)	(148.7)	(173.0)
Acquisitions, net of cash acquired	(28.6)	(67.8)	(61.5)
Proceeds from sales of businesses, investments and fixed assets, net of cash sold	(12.1)	18.8	2.5
Net sales (purchases) and maturities of short-term marketable securities	0.1	(0.6)	10.8
Other investing activities	(1.1)	(2.5)	(3.3)
Net cash used in investing activities	(202.8)	(200.8)	(224.5)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repurchase of common stock	(285.2)	(275.1)	(481.8)
Common stock dividends	(195.5)	(159.0)	(126.0)
Acquisition-related payments	(53.1)	(13.6)	(27.6)
Distributions to noncontrolling interests	(15.9)	(17.0)	(14.9)
Purchase of long-term debt	(2.0)	(351.2)	(602.4)
Proceeds from Issuance of Long-term Debt	0.1	499.1	0.0
Net increase (decrease) in short term bank borrowings	52.3	(63.2)	5.4
Exercise of stock options	13.5	20.1	47.4
Excess tax benefit on share-based compensation	10.2	16.7	0.0
Preferred stock dividends	0.0	0.0	(11.6)
Other financing activities	2.8	(0.7)	(0.8)
Net cash used in financing activities	(472.8)	(343.9)	(1,212.3)
Effect of foreign exchange rate changes on cash and cash equivalents	(156.1)	(101.0)	(94.1)
Net (decrease) increase in cash and cash equivalents	(157.7)	23.8	(938.0)
Cash and cash equivalents at beginning of period	1,660.6	1,636.8	2,574.8
Cash and cash equivalents at end of period	$ 1,502.9	$ 1,660.6	$ 1,636.8

Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss, Net of Tax	Treasury Stock	Total IPG Stockholders' Equity	Noncontrolling Interests
Balance at Dec. 31, 2012	$ 2,456.6	$ 221.5	$ 48.8	$ 2,465.4	$ 738.3	$ (288.0)	$ (765.4)	$ 2,420.6	$ 36.0
Balance, shares at Dec. 31, 2012			492.0
Net income	288.9				267.9			267.9	21.0
Other comprehensive loss	(127.1)					(123.2)		(123.2)	(3.9)
Reclassifications related to redeemable noncontrolling interests	(4.4)			0.2				0.2	(4.6)
Noncontrolling interest transactions	1.0			(0.1)				(0.1)	1.1
Distributions to noncontrolling interests	(14.9)								(14.9)
Change in redemption value of redeemable noncontrolling interests	(6.2)				(6.2)			(6.2)
Repurchase of common stock	(481.8)						(481.8)	(481.8)
Common stock dividends	(126.0)				(126.0)			(126.0)
Preferred stock dividends	(8.7)				(8.7)			(8.7)
Conversion of convertible notes to common stock, shares			16.9
Conversion of convertible notes to common stock	200.0		$ 1.7	198.3				200.0
Capped call transaction	0.0			19.1			(19.1)	0.0
Conversion of preferred stock to common stock, shares		(221.5)	17.3
Conversion of preferred stock to common stock	0.0		$ 1.7	219.8				0.0
Stock-based compensation, shares			2.4
Stock-based compensation, Value	43.6		$ 0.5	43.1				43.6
Exercise of stock options, shares			5.2
Exercise of stock options, Value	47.9		$ 0.5	47.4				47.9
Shares withheld for taxes, shares			(1.5)
Shares withheld for taxes, Value	(20.1)		$ (0.2)	(19.9)				(20.1)
Other	2.0			1.9	(0.8)			1.1	0.9
Balance, shares at Dec. 31, 2013			532.3
Balance at Dec. 31, 2013	2,250.8	$ 0.0	$ 53.0	2,975.2	864.5	(411.2)	(1,266.3)	2,215.2	35.6
Net income	505.4				477.1			477.1	28.3
Other comprehensive loss	(228.1)					(225.5)		(225.5)	(2.6)
Reclassifications related to redeemable noncontrolling interests	(7.7)			(3.5)				(3.5)	(4.2)
Noncontrolling interest transactions	(2.3)			2.1				2.1	(4.4)
Distributions to noncontrolling interests	(17.0)								(17.0)
Change in redemption value of redeemable noncontrolling interests	1.5				1.5			1.5
Repurchase of common stock	(275.1)						(275.1)	(275.1)
Retirement of treasury stock, shares			(121.9)
Retirement of treasury stock	0.0		$ (12.2)	(1,510.2)			1,522.4	0.0
Common stock dividends	(159.0)				(159.0)			(159.0)
Stock-based compensation, shares			3.4
Stock-based compensation, Value	63.8		$ 0.3	63.5				63.8
Exercise of stock options, shares			1.7
Exercise of stock options, Value	20.3		$ 0.2	20.1				20.3
Shares withheld for taxes, shares			(0.9)
Shares withheld for taxes, Value	(15.0)		$ (0.1)	(14.9)				(15.0)
Excess tax benefit from stock-based compensation	15.2			15.2				15.2
Other	(1.6)				(0.8)			(0.8)	(0.8)
Balance, shares at Dec. 31, 2014			414.6
Balance at Dec. 31, 2014	2,151.2	0.0	$ 41.2	1,547.5	1,183.3	(636.7)	(19.0)	2,116.3	34.9
Net income	480.5				454.6			454.6	25.9
Other comprehensive loss	(213.1)					(208.9)		(208.9)	(4.2)
Reclassifications related to redeemable noncontrolling interests	(6.0)								(6.0)
Noncontrolling interest transactions	1.2								1.2
Distributions to noncontrolling interests	(15.9)								(15.9)
Change in redemption value of redeemable noncontrolling interests	(3.9)				(3.9)			(3.9)
Repurchase of common stock	(285.2)						(285.2)	(285.2)
Retirement of treasury stock, shares			(11.3)
Retirement of treasury stock	0.0		$ (1.2)	(232.0)			233.2	0.0
Common stock dividends	(195.5)				(195.5)			(195.5)
Stock-based compensation, shares			2.5
Stock-based compensation, Value	83.4		$ 0.3	83.1				83.4
Exercise of stock options, shares			1.3
Exercise of stock options, Value	13.7		$ 0.2	13.5				13.7
Shares withheld for taxes, shares			(0.8)
Shares withheld for taxes, Value	(17.8)		$ (0.1)	(17.7)				(17.8)
Excess tax benefit from stock-based compensation	10.2			10.2				10.2
Other	(1.0)			(0.5)	(0.9)			(1.4)	0.4
Balance, shares at Dec. 31, 2015			406.3
Balance at Dec. 31, 2015	$ 2,001.8	$ 0.0	$ 40.4	$ 1,404.1	$ 1,437.6	$ (845.6)	$ (71.0)	$ 1,965.5	$ 36.3

Significant Accounting Policies (Notes)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Business Description

The Interpublic Group of Companies, Inc. and subsidiaries (the “Company,” “IPG,” “we,” “us” or “our”) is one of the world’s premier global advertising and marketing services companies. Our agencies create customized marketing programs for clients that range in scale from large global marketers to regional and local clients. Comprehensive global services are critical to effectively serve our multinational and local clients in markets throughout the world, as they seek to build brands, increase sales of their products and services and gain market share in an increasingly complex and fragmented media landscape.

Principles of Consolidation

The Consolidated Financial Statements include the accounts of the Company and its consolidated subsidiaries, some of which are not wholly owned. Investments in companies over which we do not have control, but have the ability to exercise significant influence, are accounted for using the equity method of accounting. Investments in companies over which we have neither control nor have the ability to exercise significant influence are accounted for under the cost method. All intercompany accounts and transactions have been eliminated in consolidation.

We have consolidated certain entities meeting the definition of variable interest entities, and the inclusion of these entities does not have a material impact on our Consolidated Financial Statements.

Reclassifications

Certain reclassifications have been made to the prior period financial statements to conform to the current-year presentation.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires us to make judgments, assumptions and estimates that affect the amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the reporting date and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and assumptions.

Revenue Recognition

Our revenues are primarily derived from the planning and execution of multi-channel advertising, marketing and communications programs around the world. Our revenues are directly dependent upon the advertising, marketing and corporate communications requirements of our existing clients and our ability to win new clients. Our revenue is typically lowest in the first quarter and highest in the fourth quarter. This reflects the seasonal spending of our clients, incentives earned at year end on various contracts and project work that is typically completed during the fourth quarter.

Most of our client contracts are individually negotiated and, accordingly, the terms of client engagements and the bases on which we earn commissions and fees vary significantly. As is customary in the industry, our contracts generally provide for termination by either party on relatively short notice, usually 90 days.

Our client contracts are complex arrangements that may include provisions for incentive compensation and vendor rebates and credits. Our largest clients are multinational entities and, as such, we often provide services to these clients out of multiple offices and across many of our agencies. In arranging for such services, it is possible that we will enter into global, regional and local agreements. Agreements of this nature are reviewed by legal counsel to determine the governing terms to be followed by the offices and agencies involved.

Revenue for our services is recognized when all of the following criteria are satisfied: (i) persuasive evidence of an arrangement exists; (ii) the price is fixed or determinable; (iii) collectability is reasonably assured; and (iv) services have been performed. Depending on the terms of a client contract, fees for services performed can be recognized in three principal ways: proportional performance (input or output), straight-line (or monthly basis) or completed contract.

•

Fees are generally recognized as earned based on the proportional performance input method of revenue recognition in situations where our fee is reconcilable to the actual hours incurred to service the client as detailed in a contractual staffing plan, where the fee is earned on a per hour basis or where actual hours incurred are provided to the client on a periodic basis (whether or not the fee is reconcilable), with the amount of revenue recognized in these situations limited to the amount realizable under the client contract. We believe an input-based measure (the ‘hour’) is appropriate in situations where the client arrangement essentially functions as a time and out-of-pocket expense contract and the client receives the benefit of the services provided throughout the contract term.


•	Fees are recognized on a straight-line or monthly basis when service is provided essentially on a pro-rata basis and the terms of the contract support monthly basis accounting.

•

Certain fees (such as for major marketing events) are deferred until contract completion if the final act is so significant in relation to the service transaction taken as a whole or if any of the terms of the contract do not otherwise qualify for proportional performance or monthly basis recognition. Fees may also be deferred and recognized upon delivery of a project if the terms of the client contract identify individual discrete projects.

Depending on the terms of the client contract, revenue is derived from diverse arrangements involving fees for services performed, commissions, performance incentive provisions and combinations of the three. Commissions are generally earned on the date of the broadcast or publication. Contractual arrangements with clients may also include performance incentive provisions designed to link a portion of our revenue to our performance relative to either qualitative or quantitative goals, or both. Performance incentives are recognized as revenue for quantitative targets when the target has been achieved and for qualitative targets when confirmation of the incentive is received from the client.

The majority of our revenue is recorded as the net amount of our gross billings less pass-through expenses charged to a client. In most cases, the amount that is billed to clients significantly exceeds the amount of revenue that is earned and reflected in our Consolidated Financial Statements because of various pass-through expenses, such as production and media costs. We assess whether our agency or the third-party supplier is the primary obligor, and we evaluate the terms of our client agreements as part of this assessment. In addition, we give appropriate consideration to other key indicators such as latitude in establishing price, discretion in supplier selection and credit risk to the vendor. Because we operate broadly as an advertising agency, based on our primary lines of business and given the industry practice to generally record revenue on a net versus gross basis, we believe that there must be strong evidence in place to overcome the presumption of net revenue accounting. Accordingly, we generally record revenue net of pass-through charges as we believe the key indicators of the business suggest we generally act as an agent on behalf of our clients in our primary lines of business. In those businesses where the key indicators suggest we act as a principal (primarily sales promotion and event, sports and entertainment marketing), we record the gross amount billed to the client as revenue and the related incremental direct costs incurred as office and general expenses. In general, we also report revenue net of taxes assessed by governmental authorities that are directly imposed on our revenue-producing transactions.

As we provide services as part of our core operations, we generally incur incidental expenses, which, in practice, are commonly referred to as “out-of-pocket” expenses. These expenses often include expenses related to airfare, mileage, hotel stays, out-of-town meals and telecommunication charges. We record the reimbursements received for such incidental expenses as revenue with a corresponding offset to office and general expense.

We receive credits from our vendors and media outlets for transactions entered into on behalf of our clients that, based on the terms of our contracts and local law, are either remitted to our clients or retained by us. If amounts are to be passed through to clients, they are recorded as liabilities until settlement or, if retained by us, are recorded as revenue when earned.

Cash and Cash Equivalents

Cash equivalents are highly liquid investments, which include certificates of deposit, government securities, commercial paper and time deposits with original maturities of three months or less at the time of purchase and are stated at estimated fair value, which approximates cost. Cash is maintained at multiple high-credit-quality financial institutions.

Short-Term Marketable Securities

Short-term marketable securities include investment-grade time deposits, commercial paper and government securities with maturities greater than three months but less than twelve months. These securities are classified as available-for-sale and are carried at fair value with net unrealized gains and losses reported as a component of accumulated other comprehensive loss, which is a component of stockholders’ equity. The cost of securities is determined based upon the average cost of the securities sold.

Allowance for Doubtful Accounts

The allowance for doubtful accounts is estimated based on the aging of accounts receivable, reviews of client credit reports, industry trends and economic indicators, as well as reviews of recent payment history for specific customers. The estimate is based largely on a formula-driven calculation but is supplemented with economic indicators and knowledge of potential write-offs of specific client accounts.

Expenditures Billable to Clients

Expenditures billable to clients are primarily comprised of production and media costs that have been incurred but have not yet been billed to clients, as well as fees that have been earned which have not yet been billed to clients. Unbilled amounts are presented in expenditures billable to clients regardless of whether they relate to our fees or production and media costs. A provision is made for unrecoverable costs as deemed appropriate.

Accounts Payable

Accounts payable includes all operating payables, including those related to all media and production costs. These payables are due within one year.

Investments

Our investments in publicly traded companies over which we do not exert a significant influence are classified as available-for-sale. These investments are reported at fair value based on quoted market prices with net unrealized gains and losses reported as a component of accumulated other comprehensive loss. Our non-publicly traded investments and all other publicly traded investments, including investments to fund certain deferred compensation and retirement obligations, are accounted for using the equity method or cost method. We do not disclose the fair value for equity method investments or investments held at cost as it is not practical to estimate fair value since there is no readily available market data and it is cost prohibitive to obtain independent valuations. We regularly review our equity and cost method investments to determine whether a significant event or change in circumstances has occurred that may impact the fair value of each investment. In the event a decline in fair value of an investment occurs, we determine if the decline has been other-than-temporary. We consider our investments strategic and long-term in nature, so we determine if the fair value decline is recoverable within a reasonable period. For our investments, we evaluate fair value based on specific information (valuation methodologies, estimates of appraisals, financial statements, etc.) in addition to quoted market price, if available. We consider all known quantitative and qualitative factors in determining if an other-than-temporary decline in value of an investment has occurred.

Derivatives

We are exposed to market risk related to interest rates, foreign currency rates and certain balance sheet items. From time to time we enter into derivative instruments for risk management purposes, and not for speculative purposes. All derivative instruments are recorded at fair value on our balance sheet. Changes in fair value are immediately included in earnings if the derivatives are not designated as a hedge instrument or if the derivatives do not qualify as effective hedges. For derivatives designated as hedge instruments, we evaluate for hedge accounting both at inception and throughout the hedge period. If a derivative is designated as a fair value hedge, then changes in the fair value of the derivative are offset against the changes in the fair value of the underlying hedged item. If a derivative is designated as a cash flow hedge, then the effective portion of the changes in the fair value of the derivative is recognized as a component of accumulated other comprehensive income and subsequently reclassified to earnings in our Consolidated Statement of Operations in the same period as the underlying hedged transaction affects earnings.

Property and Equipment

Furniture, equipment, leasehold improvements and buildings are stated at cost, net of accumulated depreciation. Furniture and equipment are depreciated generally using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years for furniture and equipment, 10 to 35 years for buildings and the shorter of the useful life or the remaining lease term for leasehold improvements. Land is stated at cost and is not depreciated.

We capitalize certain internal and external costs incurred to acquire or create internal use software, principally related to our enterprise resource planning (“ERP”) systems. Our ERP systems are stated at cost, net of accumulated amortization and are amortized using the straight-line method over 10 years. All other internal use computer software are stated at cost, net of accumulated amortization and are amortized using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years.

Goodwill and Other Intangible Assets

We account for our business combinations using the acquisition accounting method, which requires us to determine the fair value of net assets acquired and the related goodwill and other intangible assets. Determining the fair value of assets acquired and liabilities assumed requires management's judgment and involves the use of significant estimates, including projections of future cash inflows and outflows, discount rates, asset lives and market multiples. Considering the characteristics of advertising, specialized marketing and communication services companies, our acquisitions usually do not have significant amounts of tangible assets, as the principal asset we typically acquire is creative talent. As a result, a substantial portion of the purchase price is allocated to goodwill and other intangible assets.

We review goodwill and other intangible assets with indefinite lives not subject to amortization as of October 1^st each year and whenever events or significant changes in circumstances indicate that the carrying value may not be recoverable. We evaluate the recoverability of goodwill at a reporting unit level. We have 12 reporting units that were subject to the 2015 annual impairment testing. Our annual impairment review as of October 1, 2015 did not result in an impairment charge for any of our reporting units.

For reporting units not included in the qualitative assessment, or for any reporting units identified in the qualitative assessment as "more likely than not" that the fair value is less than its carrying value, the first step of the quantitative impairment test is performed. For our annual impairment test, we compare the respective fair value of our reporting units' equity to the carrying value of their net assets. The first step is a comparison of the fair value of each reporting unit to its carrying value, including goodwill. The sum of the fair values of all our reporting units is reconciled to our current market capitalization plus an estimated control premium. Goodwill allocated to a reporting unit whose fair value is equal to or greater than its carrying value is not impaired, and no further testing is required. Should the carrying amount for a reporting unit exceed its fair value, then the first step of the quantitative impairment test is failed and the magnitude of any goodwill impairment is determined under the second step, which is a comparison of the implied fair value of a reporting unit's goodwill to its carrying value. The implied fair value of goodwill is the excess of the fair value of the reporting unit over its carrying value, excluding goodwill. Impaired goodwill is written down to its implied fair value with a charge to expense in the period the impairment is identified.

The fair value of a reporting unit for 2015 and 2014 was estimated using a combination of the income approach, which incorporates the use of the discounted cash flow method, and the market approach, which incorporates the use of earnings and revenue multiples based on market data.

We review intangible assets with definite lives subject to amortization whenever events or circumstances indicate that a carrying amount of an asset may not be recoverable. Recoverability of these assets is determined by comparing the carrying value of these assets to the estimated undiscounted future cash flows expected to be generated by these assets. These assets are impaired when their carrying value exceeds their fair value. Impaired intangible assets with definite lives subject to amortization are written down to their fair value with a charge to expense in the period the impairment is identified. Intangible assets with definite lives are amortized on a straight-line basis with estimated useful lives generally between 7 and 15 years. Events or circumstances that might require impairment testing include the loss of a significant client, the identification of other impaired assets within a reporting unit, loss of key personnel, the disposition of a significant portion of a reporting unit, significant decline in stock price or a significant adverse change in business climate or regulations.

Foreign Currencies

The functional currency of our foreign operations is generally their respective local currency. Assets and liabilities are translated at the exchange rates in effect at the balance sheet date, and revenues and expenses are translated at the average exchange rates during the period presented. The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss in the stockholders’ equity section of our Consolidated Balance Sheets. Currency transaction gains or losses primarily arising from transactions in currencies other than the functional currency are included in office and general expenses. Foreign currency transactions resulted in a pre-tax gain of $2.0 in 2015 and pre-tax losses of $1.4 and $0.6 in 2014 and 2013, respectively.

We monitor the currencies of countries in which we operate in order to determine if the country should be considered a highly inflationary environment. A currency is determined to be highly inflationary when there is cumulative inflation of approximately 100% or more over a three-year period. If this occurs the functional currency of that country would be changed to our reporting currency, the U.S. Dollar, and foreign exchange gains or losses would be recognized on all monetary transactions, assets and liabilities in currencies other than the U.S. Dollar until the currency is no longer considered highly inflationary.

Income Taxes

The provision for income taxes includes U.S. federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be reversed. We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is “more likely than not” that all or a portion of the deferred tax assets will not be realized. We evaluate our tax positions using the “more likely than not” recognition threshold and then apply a measurement assessment to those positions that meet the recognition threshold. The factors used in assessing valuation allowances include all available evidence, such as past operating results, estimates of future taxable income and the feasibility of tax planning strategies. We have established tax reserves that we believe to be adequate in relation to the potential for additional assessments in each of the jurisdictions in which we are subject to taxation. We regularly assess the likelihood of additional tax assessments in those jurisdictions and adjust our reserves as additional information or events require.

Redeemable Noncontrolling Interests

Many of our acquisitions include provisions under which the noncontrolling equity owners can require us to purchase additional interests in a subsidiary at their discretion. Payments for these redeemable noncontrolling interests may be contingent on projected operating performance and satisfying other conditions specified in the related agreements. These payments are also subject to revision in accordance with the terms of the agreements. We record these redeemable noncontrolling interests in “mezzanine equity” in our Consolidated Balance Sheets. Each reporting period, redeemable noncontrolling interests are reported at their estimated redemption value, but not less than their initial fair value. Any adjustment to the redemption value above initial value prior to exercise will also impact retained earnings or additional paid-in capital, but will not impact net income. Adjustments as a result of currency translation will affect the redeemable noncontrolling interest balance, but do not impact retained earnings or additional paid-in capital.

Earnings Per Share (“EPS”)

Basic EPS available to IPG common stockholders equals net income available to IPG common stockholders divided by the weighted-average number of common shares outstanding for the applicable period. Diluted EPS equals net income available to IPG common stockholders adjusted to exclude, if dilutive, preferred stock dividends, interest expense related to potentially dilutive securities calculated using the effective interest rate method and the benefit from the preferred stock repurchased, divided by the weighted-average number of common shares outstanding, plus any additional common shares that would have been outstanding if potentially dilutive shares had been issued.

Diluted EPS reflect the potential dilution that would occur if certain potentially dilutive securities or debt obligations were exercised or converted into common stock. The potential issuance of common stock is assumed to occur at the beginning of the year (or at the time of issuance of the potentially dilutive instrument, if later) and the incremental shares are included using the treasury stock or “if-converted” method. The proceeds utilized in applying the treasury stock method consist of the amount, if any, to be paid upon exercise and, as it relates to stock-based compensation, the amount of compensation cost attributed to future service not yet recognized and any tax benefits credited to additional paid-in-capital related to the exercise. These proceeds are then assumed to be used to purchase common stock at the average market price of our stock during the period. The incremental shares (difference between the shares assumed to be issued and the shares assumed to be purchased), to the extent they would have been dilutive, are included in the denominator of the diluted EPS calculation.

We may be required to calculate basic EPS using the two-class method as a result of our redeemable noncontrolling interests. To the extent that the redemption value increases and exceeds the then-current fair value of a redeemable noncontrolling interest, net income available to IPG common stockholders (used to calculate EPS) could be negatively impacted by that increase, subject to certain limitations. The partial or full recovery of any reductions to net income available to IPG common stockholders (used to calculate EPS) is limited to any cumulative prior-period reductions. For the years ended December 31, 2015, 2014 and 2013, there was no impact to EPS for adjustments related to our redeemable noncontrolling interests.

Pension and Postretirement Benefits

We have pension and postretirement benefit plans covering certain domestic and international employees. We use various actuarial methods and assumptions in determining our net pension and postretirement benefit costs and obligations, including the discount rate used to determine the present value of future benefits, expected long-term rate of return on plan assets and healthcare cost trend rates. The overfunded or underfunded status of our pension and postretirement benefit plans is recorded on our Consolidated Balance Sheet.

Stock-Based Compensation

Compensation costs related to share-based transactions, including employee stock options, are recognized in the Consolidated Financial Statements based on fair value. Stock-based compensation expense is generally recognized ratably over the requisite service period based on the estimated grant-date fair value, net of estimated forfeitures.

Treasury Stock

We account for repurchased common stock under the cost method and include such treasury stock as a component of our Consolidated Statements of Stockholders' Equity. Upon retirement, we reduce common stock for the par value of the shares being retired and the excess of the cost of the shares over par value as a reduction to additional paid-in capital ("APIC"), to the extent there is APIC in the same class of stock, and any remaining amount to retained earnings. These retired shares remain authorized but unissued.

In October 2015, we retired 11.3 shares of our treasury stock, which resulted in a reduction in common stock of $1.2, treasury stock of $233.2 and APIC of $232.0. There was no effect on total stockholders' equity as a result of the retirement. In November 2014, we retired 121.9 shares of our treasury stock, which resulted in a reduction in common stock of $12.2, treasury stock of $1,522.4 and APIC of $1,510.2. There was no effect on total stockholders' equity as a result of the retirement.

Debt and Credit Agreements (Notes)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Debt Disclosure [Text Block]

Debt and Credit Arrangements

Long-Term Debt

A summary of the carrying amounts and fair values of our long-term debt is listed below.



	Effective Interest Rate		December 31,
			2015				2014
			Book Value		Fair Value ¹		Book Value		Fair Value ¹
2.25% Senior Notes due 2017 (less unamortized discount and issuance costs of $0.3 and $0.9, respectively)	2.30	%	$	298.8	$	299.3	$	298.3	$	301.2
4.00% Senior Notes due 2022 (less unamortized discount and issuance costs of $2.0 and $1.6, respectively)	4.13	%	246.4		250.9		245.9		255.2
3.75% Senior Notes due 2023 (less unamortized discount and issuance costs of $1.1 and $2.9, respectively)	4.32	%	496.0		484.8		495.5		499.8
4.20% Senior Notes due 2024 (less unamortized discount and issuance costs of $0.8 and $3.4, respectively)	4.24	%	495.8		496.4		495.0		509.8
Other notes payable and capitalized leases			75.2		75.2		80.3		80.3
Total long-term debt			1,612.2				1,615.0
Less: current portion			1.9				2.1
Long-term debt, excluding current portion			$	1,610.3			$	1,612.9


1	See Note 11 for information on the fair value measurement of our long-term debt.

Annual maturities are scheduled as follows based on the book value as of December 31, 2015.



2016	$	1.9
2017	323.3
2018	1.8
2019	1.8
2020	0.9
Thereafter	1,282.5
Total long-term debt	$	1,612.2

For those debt securities that have a premium or discount at the time of issuance, we amortize the amount through interest expense based on the maturity date or the first date the holders may require us to repurchase the debt securities, if applicable. A premium would result in a decrease in interest expense and a discount would result in an increase in interest expense in future periods.

Additionally, we have debt issuance costs related to certain financing transactions which are also amortized through interest expense. In April 2015, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update No. 2015-03 which requires debt issuance costs to be presented as a direct deduction from the carrying value of the associated debt liability rather than as separate assets on the balance sheet. The FASB later issued guidance in August 2015 stating that debt issuance costs related to line-of-credit arrangements may be presented as an asset and subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. We have adopted this amended guidance as of the quarter ended December 31, 2015. As a result of this adoption, $8.9 and $10.6 of debt issuance costs were reclassified from Other non-current assets to Long-term debt in our Consolidated Balance Sheets as of December 31, 2015 and 2014, respectively. Debt issuance costs associated with our committed corporate credit facility continue to be recorded within Other non-current assets in our Consolidated Balance Sheets. As of December 31, 2015 and 2014, we had total unamortized debt issuance costs of $15.0 and $16.6, respectively.

Our debt securities include covenants that, among other things, limit our liens and the liens of certain of our consolidated subsidiaries, but do not require us to maintain any financial ratios or specified levels of net worth or liquidity.

Debt Transactions

6.25% Senior Unsecured Notes due 2014

In May 2014, we redeemed all $350.0 in aggregate principal amount of our 6.25% Senior Unsecured Notes due 2014 (the "6.25% Notes"). Total cash paid to redeem the 6.25% Notes was $371.2, which included accrued and unpaid interest of $10.3. In connection with the redemption of the 6.25% Notes, we recognized a loss on early extinguishment of debt of $10.4, primarily due to a redemption premium. The loss on early extinguishment of debt was recorded in Other expense, net within our Consolidated Statement of Operations.

4.20% Senior Notes due 2024

In April 2014, we issued $500.0 in aggregate principal amount of the 4.20% Senior Notes due 2024 (the "4.20% Notes") at a discount to par. As a result, the 4.20% Notes were reflected on our Consolidated Balance Sheets at a fair value of $499.1 at issuance. The discount of $0.9 and capitalized direct fees, including commissions and offering expenses of $4.4, will be amortized in interest expense through the maturity date of April 15, 2024, using the effective interest method. The net proceeds were $494.7 after deducting discounts, commissions and offering expenses. Interest is payable semi-annually in arrears on April 15th and October 15th of each year, commencing on October 15, 2014. Consistent with our other debt securities, the 4.20% Notes include covenants that, among other things, limit our liens and the liens of certain of our consolidated subsidiaries but do not require us to maintain any financial ratios or specified levels of net worth or liquidity.

We used the majority of the net proceeds of the 4.20% Notes toward the redemption of our 6.25% Notes as described above.

At any time prior to April 15, 2024, at our option, we may redeem all or some of the 4.20% Notes at the greater of 100% of the principal amount or a "make-whole" amount, plus, in either instance, accrued and unpaid interest to the date of redemption. If we experience a change of control event, combined with a specified downgrade in the credit rating, we must offer to repurchase the 4.20% Notes in cash at a price equal to not less than 101% of the aggregate principal amount of the 4.20% Notes, plus accrued and unpaid interest to the date of repurchase.

Credit Agreements

We maintain a committed corporate credit facility and uncommitted credit facilities with various banks that permit borrowings at variable interest rates. As of December 31, 2015 and 2014, there were no borrowings under our committed corporate credit facility. However, there were borrowings under some of the uncommitted facilities to manage working capital needs. We have guaranteed the repayment of some of these borrowings made by certain subsidiaries. If we lose access to these credit lines, we would have to provide funding directly to some of our international operations. The weighted-average interest rate on outstanding balances under the uncommitted credit facilities as of December 31, 2015 and 2014 was approximately 3% and 5%, respectively.

A summary of our credit facilities is presented below.



	December 31,
	2015								2014
	Total Facility		Amount Outstanding		Letters of Credit		Total Available		Total Facility		Amount Outstanding		Letters of Credit		Total Available
Committed credit agreement	$	1,000.0	$	0.0	$	3.7	$	996.3	$	1,000.0	$	0.0	$	16.0	$	984.0
Uncommitted credit agreements	$	744.5	$	150.1	$	1.1	$	593.3	$	740.3	$	107.2	$	3.9	$	629.2

On October 20, 2015, we amended and restated our credit agreement, originally dated as of July 18, 2008 (as amended and restated, the "Credit Agreement"). The Credit Agreement is a revolving facility, with a maturity date of October 20, 2020, under which amounts borrowed by us or any of our subsidiaries designated under the Credit Agreement may be repaid and reborrowed, subject to an aggregate lending limit of $1,000.0, or the equivalent in other currencies. The Company has the ability to increase the commitments under the Credit Agreement from time to time by an additional amount of up to $250.0, provided the Company receives commitments for such increases and satisfies certain other conditions. The aggregate available amount of letters of credit outstanding may decrease or increase, subject to a sublimit on letters of credit of $200.0 or the equivalent in other currencies. Our obligations under the Credit Agreement are unsecured.

Under the Credit Agreement, we can elect to receive advances bearing interest based on either the base rate or the Eurocurrency rate (each as defined in the Credit Agreement) plus an applicable margin that is determined based on our credit ratings. As of December 31, 2015, the applicable margin was 0.30% for base rate advances and 1.30% for Eurocurrency rate advances. Letter of credit fees accrue on the average daily aggregate amount of letters of credit outstanding, at a rate equal to the applicable margin for Eurocurrency rate advances, and fronting fees accrue on the aggregate amount of letters of credit outstanding at an annual rate of 0.25%. We also pay a facility fee at an annual rate that is determined based on our credit ratings, which as of December 31, 2015, was 0.20% on the aggregate lending commitment under the Credit Agreement.

In addition to other and customary covenants, the Credit Agreement requires that we maintain the financial covenants listed below as of the end of each fiscal quarter for the period of four fiscal quarters then ended.



Interest coverage ratio (not less than): ¹		5.00x
Leverage ratio (not greater than): ²		3.50x


1	The interest coverage ratio is defined as EBITDA, as defined in the Credit Agreement, to net interest expense.

The leverage ratio is defined as debt as of the last day of such fiscal quarter to EBITDA, as defined in the Credit Agreement, for the four quarters then ended. The leverage ratio may be changed to not more than 4.00 to 1 at our election for four consecutive fiscal quarters, beginning with the fiscal quarter in which there is an occurrence of one or more acquisitions with an aggregate purchase price of at least $200.0.

We were in compliance with all of our covenants in the Credit Agreement as of December 31, 2015.

Cash Pooling

We aggregate our domestic cash position on a daily basis. Outside the United States, we use cash pooling arrangements with banks to help manage our liquidity requirements. In these pooling arrangements, several IPG agencies agree with a single bank that the cash balances of any of the agencies with the bank will be subject to a full right of set-off against amounts other agencies owe the bank, and the bank provides for overdrafts as long as the net balance for all agencies does not exceed an agreed-upon level. Typically, each agency pays interest on outstanding overdrafts and receives interest on cash balances. Our Consolidated Balance Sheets reflect cash, net of bank overdrafts, under all of our pooling arrangements, and as of December 31, 2015 and 2014 the amounts netted were $1,608.3 and $1,590.7, respectively.

Earnings Per Share (Notes)

12 Months Ended

Dec. 31, 2015

Earnings Per Share [Abstract]

Earnings Per Share

The following sets forth basic and diluted earnings per common share available to IPG common stockholders.



	Years ended December 31,
	2015		2014		2013
Net income available to IPG common stockholders - basic	$	454.6	$	477.1	$	259.2
Adjustments: Effect of dilutive securities
Interest on 4.75% Notes ¹	0.0		0.0		0.8
Net income available to IPG common stockholders - diluted	$	454.6	$	477.1	$	260.0


Weighted-average number of common shares outstanding - basic	408.1		419.2		421.1
Add: Effect of dilutive securities
Restricted stock, stock options and other equity awards	7.6		6.2		5.2
4.75% Notes ¹	0.0		0.0		3.3

Weighted-average number of common shares outstanding - diluted	415.7		425.4		429.6


Earnings per share available to IPG common stockholders - basic	$	1.11	$	1.14	$	0.62
Earnings per share available to IPG common stockholders - diluted	$	1.09	$	1.12	$	0.61


1	We retired all of our outstanding 4.75% Convertible Senior Notes due 2023 (the "4.75% Notes") in March 2013. For purposes of calculating diluted earnings per share for 2013, the potentially dilutive shares are pro-rated based on the period in which they were outstanding.

The following table presents the potential shares excluded from the diluted earnings per share calculation because the effect of including these potential shares would be antidilutive.



	Years ended December 31,
	2015	2014	2013
Preferred Stock Outstanding ¹	0.0	0.0	13.7
Securities excluded from the diluted earnings per share calculation because the exercise price was greater than the average market price:
Stock options ²	0.0	0.0	0.1


1	We converted all of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock into common stock in October 2013. For purposes of calculating diluted earnings per share for 2013, the potentially dilutive shares would have been pro-rated based on the period they were outstanding but were antidilutive.


2	These options were outstanding at the end of the respective periods. In any period in which the exercise price is less than the average market price, these options have the potential to be dilutive, and application of the treasury stock method would reduce this amount.

Acquisitions (Notes)

12 Months Ended

Dec. 31, 2015

Business Combinations [Abstract]

Acquisitions

We continue to evaluate strategic opportunities to expand our industry expertise, strengthen our position in high-growth and key strategic geographical markets and industry sectors, advance technological capabilities and improve operational efficiency through both acquisitions and increased ownership interests in current investments. Our acquisitions typically provide for an initial payment at the time of closing and additional contingent purchase price payments based on the future performance of the acquired entity. We have entered into agreements that may require us to purchase additional equity interests in certain consolidated and unconsolidated subsidiaries. The amounts at which we record these transactions in our financial statements are based on estimates of the future financial performance of the acquired entity, the timing of the exercise of these rights, changes in foreign currency exchange rates and other factors.

For companies acquired, we estimate the fair values of the assets and liabilities based on 100% of the business for consolidation. The purchase price in excess of the estimated fair value of the tangible net assets acquired is allocated to identifiable intangible assets and then to goodwill. Due to the characteristics of advertising, specialized marketing and communication services companies, our acquisitions typically do not have significant amounts of tangible assets since the principal assets we acquire are client relationships and talent. As a result, a substantial portion of the purchase price is primarily allocated to customer lists, trade names and goodwill.

For acquisitions we record deferred payment and redeemable noncontrolling interest amounts on our Consolidated Balance Sheets based on their acquisition-date fair value. Deferred payments are recorded on a discounted basis and adjusted quarterly, if necessary, through operating income or net interest expense, depending on the nature of the arrangement, for both changes in estimate and accretion between the acquisition date and the final payment date. See Note 14 for further information on contingent acquisition obligations. Redeemable noncontrolling interests are adjusted quarterly to their estimated redemption value, but not less than their initial fair value. Any adjustments to the redemption value impacts retained earnings, except for foreign currency translation adjustments. The following table presents changes in our redeemable noncontrolling interests.



	Years ended December 31,
	2015			2014			2013
Balance at beginning of period	$	257.4		$	249.1		$	227.2
Change in related noncontrolling interest balance	0.8			3.2			4.6
Changes in redemption value of redeemable noncontrolling interests:
Additions	16.5			18.7			16.2
Redemptions and reclassifications	(25.1		)	(7.9		)	(2.3		)
Redemption value adjustments	2.3			(5.7		)	3.4
Balance at end of period	$	251.9		$	257.4		$	249.1

For all acquisitions, if a portion of the deferred payments and purchases of additional interests after the effective date of purchase are contingent upon employment terms, then that amount is accounted separately from the business combination and recognized as compensation expense over the required earn-out period. Payments deemed as compensation are excluded from the fair value purchase price allocation to tangible net assets and intangible assets acquired.

During 2015, we completed five acquisitions, four of which were included in the Integrated Agency Networks ("IAN") operating segment and one of which was included in the Constituency Management Group ("CMG") operating segment. All acquired agencies have been integrated into one of our global networks or existing agencies. The most significant acquisitions include a full-service digital agency in the U.K., a group of creative marketing agencies based in Russia, and a media planning and buying agency with significant digital capabilities in Canada. During 2015, we recorded approximately $61.0 of goodwill and intangible assets related to our acquisitions.

During 2014, we completed eight acquisitions, six of which were included in the IAN operating segment and two of which were included in the CMG operating segment. All acquired agencies have been integrated into one of our global networks or existing agencies. The most significant acquisitions included a global full-service digital agency, a digital agency in the United States and a search marketing agency in the Netherlands. During 2014, we recorded approximately $185.0 of goodwill and intangible assets related to these acquisitions.

During 2013, we completed eleven acquisitions, nine of which were included in the IAN operating segment and two of which were included in the CMG operating segment. All acquired agencies have been integrated into one of our global networks or existing agencies. The most significant acquisitions included a full-service digital agency in India, a full-service agency in the U.K. and a public relations consultancy in India. During 2013, we recorded approximately $97.0 of goodwill and intangible assets related to these acquisitions.

The results of operations of our acquired companies were included in our consolidated results from the closing date of each acquisition. We did not make any payments in stock related to our acquisitions in 2015, 2014 or 2013.

Details of cash paid for current and prior years' acquisitions are listed below.



	Years ended December 31,
	2015			2014			2013
Cost of investment: current-year acquisitions	$	37.8		$	97.3		$	67.7
Cost of investment: prior-year acquisitions	53.1			14.0			28.5
Less: net cash acquired	(9.2		)	(29.9		)	(7.1		)
Total cost of investment	81.7			81.4			89.1
Operating expense¹	18.4			3.4			2.0

Total cash paid for acquisitions ²	$	100.1		$	84.8		$	91.1


1	Represents cash payments made that were either in excess of the initial value of contingent payments or contingent upon the future employment of the former owners of the acquired companies and are recorded in the operating section of the Consolidated Statements of Cash Flows.

Of the total cash paid for acquisitions, $53.1, $13.6 and $27.6 for the years ended December 31, 2015, 2014 and 2013, respectively, are classified under the financing section of the Consolidated Statements of Cash Flows as acquisition-related payments. These amounts relate to deferred payments and increases in our ownership interest for prior acquisitions. $28.6, $67.8 and $61.5 for the years ended December 31, 2015, 2014 and 2013, respectively, are classified under the investing section of the Consolidated Statements of Cash Flows as acquisitions, net of cash acquired. These amounts relate to initial payments for new transactions.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

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-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4922-128472

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4934-128472

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=56956791&loc=d3e4926-128472

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1383-128463

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6996-128479

+ Details

Supplementary Data (Notes)

12 Months Ended

Dec. 31, 2015

Supplementary Data [Abstract]

Supplementary Data

Valuation and Qualifying Accounts – Allowance for Uncollectible Accounts Receivable



	Years ended December 31,
	2015			2014			2013
Balance at beginning of period	$	59.5		$	64.9		$	59.0
Charges to costs and expenses	11.4			7.4			12.6
(Reversals) charges to other accounts ¹	(0.4		)	0.1			0.7
Deductions:
Dispositions	(2.4		)	0.0			0.0
Uncollectible accounts written off	(9.8		)	(8.1		)	(7.2		)
Foreign currency translation adjustment	(4.1		)	(4.8		)	(0.2		)
Balance at end of period	$	54.2		$	59.5		$	64.9


1	Amounts primarily represent miscellaneous reclassifications and allowances of acquired companies.

Property and Equipment



	December 31,
	2015			2014
Furniture and equipment	$	585.1		$	640.7
Leasehold improvements	570.1			594.0
Internal use computer software	295.2			296.2
Land and buildings	78.7			87.3
	1,529.1			1,618.2
Less: accumulated depreciation	(961.9		)	(1,070.0		)
Total property and equipment, net	$	567.2		$	548.2

The total depreciation and amortization expense for property and equipment for the years ended December 31, 2015, 2014 and 2013 was $130.9, $133.7 and $133.2, respectively.

Accrued Liabilities

The following table presents the components of accrued liabilities.



	December 31,
	2015		2014
Salaries, benefits and related expenses	$	502.4	$	510.6
Office and related expenses	51.0		51.5
Acquisition obligations	50.1		88.1
Interest	17.3		18.3
Restructuring and other reorganization-related	3.3		5.5
Other	136.2		122.0
Total accrued liabilities	$	760.3	$	796.0

Other Expense, net

Results of operations include certain items that are not directly associated with our revenue-producing operations.



	Years ended December 31,
	2015			2014			2013
(Losses) gains on sales of businesses and investments, net	$	(49.6	)	$	0.8		$	1.5
Loss on early extinguishment of debt	0.0			(10.4		)	(45.2		)
Vendor discounts and credit adjustments	0.8			3.3			8.6
Other income (expense), net	2.1			(3.9		)	2.8
Total other expense, net	$	(46.7	)	$	(10.2	)	$	(32.3	)

(Losses) Gains on Sales of Businesses and Investments, net – During 2015, we recognized losses on the sales of businesses on completed dispositions within both our IAN and CMG segments and the classification of certain assets as held for sale within our IAN segment. During 2014, we recognized gains from the sale of a business located in Continental Europe within our IAN segment and the sale of investments in our Rabbi Trusts, which were partially offset by a loss from the sale of a business in the domestic market within our IAN segment. During 2013, we recognized gains from the sale of marketable securities in the Asia Pacific region within our IAN segment and the sale of investments in our Rabbi Trusts, which were partially offset by a loss from the sale of a business in the United Kingdom within our IAN segment.

Assets held for sale of $12.1 and liabilities held for sale of $11.9 are included in Other current assets and Accrued liabilities, respectively, on our Consolidated Balance Sheet as of December 31, 2015. These assets and liabilities held for sale, which primarily consist of accounts receivable and accounts payable, respectively, are related to sales of businesses expected to be completed within the next twelve months.

Loss on Early Extinguishment of Debt – During 2014, we recorded a charge of $10.4 related to the redemption of our 6.25% Notes. During 2013, we recorded a charge of $45.2 related to the redemption of our 10.00% Senior Unsecured Notes due 2017. Notes. See Note 2 to the Consolidated Financial Statements for further information.

Other Expense, net

Results of operations include certain items that are not directly associated with our revenue-producing operations.



	Years ended December 31,
	2015			2014			2013
(Losses) gains on sales of businesses and investments, net	$	(49.6	)	$	0.8		$	1.5
Loss on early extinguishment of debt	0.0			(10.4		)	(45.2		)
Vendor discounts and credit adjustments	0.8			3.3			8.6
Other income (expense), net	2.1			(3.9		)	2.8
Total other expense, net	$	(46.7	)	$	(10.2	)	$	(32.3	)

Vendor Discounts and Credit Adjustments – In connection with the liabilities related to vendor discounts and credits established as part of the restatement we presented in our 2004 Annual Report on Form 10-K, these adjustments reflect the reversal of certain of these liabilities primarily where the statute of limitations has lapsed, or as a result of differences resulting from settlements with clients or vendors.

Other Income (Expense), net – During 2015, we recorded a gain related to foreign currency forward exchange contracts within our Corporate and other segment. During 2014, we recorded an other-than-temporary impairment on an investment in an unconsolidated affiliate in the Asia Pacific region within our IAN segment. During 2013, other income (expense), net primarily included a non-cash gain on re-measurement to fair value of an equity interest in an affiliate, located in the Asia Pacific region within our CMG segment, upon acquiring a controlling interest.

Share Repurchase Program

In February 2013, our Board of Directors (the "Board") authorized a new share repurchase program to repurchase from time to time up to $300.0, excluding fees, of our common stock (the "2013 Share Repurchase Program"). In March 2013, the Board authorized an increase in the amount available under our 2013 Share Repurchase Program up to $500.0, excluding fees, of our common stock to be used towards the repurchase of shares resulting from the conversion to common stock of the 4.75% Notes. In February 2014, the Board authorized a new share repurchase program to repurchase from time to time up to $300.0, excluding fees, of our common stock (the "2014 Share Repurchase Program"). In February 2015, the Board authorized a new share repurchase program to repurchase from time to time up to $300.0, excluding fees, of our common stock (the "2015 Share Repurchase Program").

We may effect such repurchases through open market purchases, trading plans established in accordance with SEC rules, derivative transactions or other means. We expect to continue to repurchase our common stock in future periods, although the timing and amount of the repurchases will depend on market conditions and other funding requirements.

The following table presents our share repurchase activity under our share repurchase programs.



	Years ended December 31,
	2015		2014		2013
Number of shares repurchased	13.6		14.9		31.8
Aggregate cost, including fees	$	285.2	$	275.1	$	481.8
Average price per share, including fees	$	20.97	$	18.41	$	15.17

We fully utilized the 2013 Share Repurchase Program in the third quarter of 2014 and the 2014 Share Repurchase Program in the third quarter of 2015. As of December 31, 2015, $158.6 remained available for repurchase under the 2015 Share Repurchase Program. The 2015 Share Repurchase Program has no expiration date.

Supplemental Cash Flow Information



	Years ended December 31,
	2015		2014		2013
Cash paid for interest	$	74.5	$	78.1	$	110.7
Cash paid for income taxes, net of refunds ¹	231.9		103.9		111.8


1	Refunds of $13.0, $21.3 and $15.0 were received for the years ended December 31, 2015, 2014 and 2013, respectively.

Intangible Assets Goodwill and Intangible Assets (Notes)

12 Months Ended

Dec. 31, 2015

Goodwill and Intangible Assets [Abstract]

Goodwill and Intangible Assets Disclosure [Text Block]

Intangible Assets

Goodwill

Goodwill is the excess purchase price remaining from an acquisition after an allocation of purchase price has been made to identifiable assets acquired and liabilities assumed based on estimated fair values. The changes in the carrying value of goodwill for our segments, IAN and CMG, for the years ended December 31, 2015 and 2014 are listed below.



	IAN			CMG			Total ¹
Balance as of December 31, 2013	$	3,097.0		$	532.0		$	3,629.0
Current-year acquisitions	95.2			40.9			136.1
Foreign currency and other	(83.7		)	(12.2		)	(95.9		)
Balance as of December 31, 2014	$	3,108.5		$	560.7		$	3,669.2
Current-year acquisitions	37.8			13.2			51.0
Foreign currency and other	(94.9		)	(16.8		)	(111.7		)
Balance as of December 31, 2015	$	3,051.4		$	557.1		$	3,608.5


1	For all periods presented, we have not recorded a goodwill impairment charge.

See Note 1 for information regarding our annual impairment methodology.

Other Intangible Assets

Other intangible assets are comprised of both assets with indefinite lives not subject to amortization and assets with definite lives subject to amortization. Other intangible assets primarily consist of customer lists and trade names, which have definitive lives and are subject to amortization on a straight-line basis with estimated useful lives generally between 7 and 15 years. Amortization expense for other intangible assets for the years ended December 31, 2015, 2014 and 2013 was $26.1, $29.4 and $26.8, respectively. There were no material impairment charges on other intangibles for the years ended December 31, 2015, 2014 and 2013. During 2015 and 2014, we recorded approximately $9.6 and $48.6 of intangible assets related to our acquisitions in the respective year.

The following table provides a summary of other intangible assets, which are included in other assets on our Consolidated Balance Sheets.



	December 31,
	2015							2014
	Gross Amount		Accumulated Amortization			Net Amount		Gross Amount		Accumulated Amortization			Net Amount
Customer lists	$	249.0	$	(150.0	)	$	99.0	$	255.8	$	(139.3	)	$	116.5
Trade names	65.0		(25.7		)	39.3		71.0		(22.8		)	48.2
Other	13.7		(3.7		)	10.0		14.1		(3.8		)	10.3
Total	$	327.7	$	(179.4	)	$	148.3	$	340.9	$	(165.9	)	$	175.0

The estimated annual amortization expense for other intangible assets for the next five years as of December 31, 2015 is listed below.



	2016		2017		2018		2019		2020
Estimated amortization expense	$	23.2	$	21.7	$	20.1	$	17.1	$	16.0

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Income Taxes Income Taxes (Notes)

12 Months Ended

Dec. 31, 2015

Income Taxes [Abstract]

Income Tax Disclosure [Text Block]

Income Taxes

The components of income before income taxes are listed below.



	Years ended December 31,
	2015		2014		2013
Domestic	$	461.0	$	387.7	$	255.3
Foreign	301.2		333.0		212.7
Total	$	762.2	$	720.7	$	468.0

The provision for income taxes is listed below.



	Years ended December 31,
	2015			2014			2013
U.S. federal income taxes (including foreign withholding taxes):
Current	$	117.8		$	8.0		$	46.9
Deferred	46.9			130.7			25.2
	164.7			138.7			72.1
State and local income taxes:
Current	15.1			9.7			(14.7		)
Deferred	13.0			23.8			24.7
	28.1			33.5			10.0
Foreign income taxes:
Current	100.4			115.3			79.6
Deferred	(10.4		)	(71.0		)	19.5
	90.0			44.3			99.1
Total	$	282.8		$	216.5		$	181.2

A reconciliation of the effective income tax rate as reflected in our Consolidated Statements of Operations to the U.S. federal statutory income tax rate is listed below.



	Years ended December 31,
	2015			2014			2013
U.S. federal statutory income tax rate	35.0		%	35.0		%	35.0		%

Income tax provision at U.S. federal statutory rate	$	266.8		$	252.3		$	163.8
State and local income taxes, net of federal income tax benefit	18.3			21.4			6.5
Impact of foreign operations, including withholding taxes	16.1			1.7			30.5
Change in net valuation allowance ¹	(20.6		)	(66.0		)	3.2
Worthless securities deduction	0.0			0.0			(22.2		)
Divestitures	11.9			0.0			0.0
Other	(9.7		)	7.1			(0.6		)
Provision for income taxes	$	282.8		$	216.5		$	181.2

Effective income tax rate on operations	37.1		%	30.0		%	38.7		%


1	Reflects changes in valuation allowance that impacted the effective income tax rate for each year presented.

In 2015, our effective income tax rate of 37.1% was negatively impacted primarily by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances and from the losses on sales of businesses for which we did not receive a full tax benefit. The negative impacts to our tax rates were partially offset by the recognition of previously unrecognized tax benefits as a result of the reversal of valuation allowances in Continental Europe and the settlement of the 2010 U.S. federal income tax audit.

In 2014, our effective income tax rate of 30.0% was positively impacted from changes to our valuation allowances of $66.0. The primary drivers of the net change were associated with a valuation allowance reversal of $124.8 in one jurisdiction partially offset by the establishment of a valuation allowance of $57.2 in another jurisdiction, both in Continental Europe. In addition, our effective income tax rate was negatively impacted by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances.

In 2013, our effective income tax rate of 38.7% was positively impacted by the recognition of previously unrecognized tax benefits as a result of the recognition of losses attributable to worthless securities in a consolidated subsidiary and the settlement of the 2002-2006 New York State audit cycle. Our effective income tax rate was negatively impacted primarily by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances.

The components of deferred tax assets and liabilities are listed below.



	December 31,
	2015			2014
Postretirement/post-employment benefits	$	25.3		$	27.4
Deferred compensation	193.4			191.2
Pension costs	25.8			41.4
Basis differences in fixed assets	(67.5		)	(38.5		)
Rent	41.1			45.8
Interest	60.9			60.9
Accruals and reserves	29.4			34.8
Allowance for doubtful accounts	10.8			10.8
Basis differences in intangible assets	(408.2		)	(412.3		)
Investments in equity securities	(8.3		)	(2.6		)
Tax loss/tax credit carry forwards	354.5			404.4
Restructuring and other reorganization-related costs	0.4			(0.3		)
Prepaid expenses	(2.3		)	0.0
Other	59.9			59.2
Total deferred tax assets, net	315.2			422.2
Valuation allowance	(275.1		)	(332.2		)
Net deferred tax assets	$	40.1		$	90.0

In November 2015, the FASB issued amended guidance which requires all deferred income tax assets and liabilities to be presented as noncurrent on the balance sheet. This amended guidance is effective beginning January 1, 2017, and may be applied retrospectively or prospectively, with early adoption permitted. We have early adopted this amended guidance and applied the presentation prospectively as of December 31, 2015. For the year ended December 31, 2014, there were $107.1 of current deferred tax assets included within Other current assets and $5.4 of current deferred tax liabilities included within Accrued liabilities, which would be classified as noncurrent under the amended guidance.

We evaluate the realizability of our deferred tax assets on a quarterly basis. The realization of our deferred tax assets is primarily dependent on future earnings. The amount of the deferred tax assets considered realizable could be reduced or increased in the near future if estimates of future taxable income are lower or greater than anticipated. A valuation allowance is established when it is “more likely than not” that all or a portion of deferred tax assets will not be realized. In circumstances where there is negative evidence, establishment of a valuation allowance is considered. The factors used in assessing valuation allowances include all available evidence, such as past operating results, estimates of future taxable income and the feasibility of tax planning strategies. We believe that cumulative losses in the most recent three-year period represent significant negative evidence, and as a result, we determined that certain of our deferred tax assets required the establishment of a valuation allowance. The deferred tax assets for which an allowance was recognized relate primarily to state and foreign tax loss carryforwards.

The change in the valuation allowance is listed below.



	Years ended December 31,
	2015			2014			2013
Balance at beginning of period	$	332.2		$	467.3		$	392.9
(Reversed) charged to costs and expenses	(20.8		)	(72.8		)	65.2
(Reversed) charged to gross tax assets and other accounts	(36.3		)	(62.3		)	9.2
Balance at end of period	$	275.1		$	332.2		$	467.3

In 2015, amounts reversed to costs and expenses primarily related to the decrease in valuation allowances in Continental Europe for existing deferred tax assets. The amounts reversed to gross tax assets and other accounts relate primarily to the effect of foreign currency translation.

In 2014, the net decrease was primarily related to a reversal of a valuation allowance for a deferred tax asset of $124.8, where we believe it is now "more likely than not" that the corresponding tax losses will be utilized over an extended period of time, based on implementing an internal financing tax action plan. This was partially offset by the establishment of a valuation allowance of $57.2, where we believe it is no longer "more likely than not" that the corresponding tax losses will be utilized, based on forecasted income not exceeding historical cumulative losses. The amounts charged to gross tax assets and other accounts relate primarily to the effect of foreign currency translation and a reduction to the valuation allowance related to the write-down of a corresponding deferred tax asset.

In 2013, amounts charged to costs and expenses primarily related to the increase in valuation allowances in the U.S. and Continental Europe regions for existing and additional deferred tax assets. The amounts charged to gross tax assets and other accounts related primarily to the effect of foreign currency translation.

As of December 31, 2015, there were $1,127.7 of loss carryforwards. These loss carryforwards were all non-U.S. tax loss carryforwards, of which $984.2 have unlimited carryforward periods and $143.5 have expiration periods from 2016 to 2035. As of December 31, 2015, the Company also had $56.7 in deferred tax assets for state net operating loss carryforwards and tax credit carryforwards, which will expire between 2016 and 2035.

As of December 31, 2015 and 2014, we had $2,592.4 and $2,214.2, respectively, of undistributed earnings attributable to foreign subsidiaries. It is our intention to permanently reinvest undistributed earnings of our foreign subsidiaries. We have not provided deferred U.S. income taxes or foreign withholding taxes on temporary differences resulting from earnings for certain foreign subsidiaries which are permanently reinvested outside the U.S. It is not practicable to determine the deferred income tax liability on these undistributed earnings because such liability, if any, is dependent on circumstances that exist if and when a remittance occurs, including the source location and amount of the distribution, the underlying tax rate already paid on the earnings, foreign withholding taxes and the opportunity to use foreign tax credits.

The table below summarizes the activity related to our unrecognized tax benefits.



	December 31,
	2015			2014			2013
Balance at beginning of period	$	238.0		$	219.2		$	194.6
Increases as a result of tax positions taken during a prior year	5.2			29.0			8.3
Decreases as a result of tax positions taken during a prior year	(19.7		)	(16.3		)	(1.9		)
Settlements with taxing authorities	(4.1		)	(1.1		)	(34.9		)
Lapse of statutes of limitation	(3.8		)	(4.1		)	(10.6		)
Increases as a result of tax positions taken during the current year	11.3			11.3			63.7
Balance at end of period	$	226.9		$	238.0		$	219.2

Included in the total amount of unrecognized tax benefits of $226.9 as of December 31, 2015, is $206.5 of tax benefits that, if recognized, would impact the effective income tax rate. The total amount of accrued interest and penalties as of December 31, 2015 and 2014 is $20.1 and $15.3, respectively, of which a detriment of $4.8 and $5.4 is included in our 2015 and 2014 Consolidated Statements of Operations, respectively. In accordance with our accounting policy, interest and penalties accrued on unrecognized tax benefits are classified as income taxes in our Consolidated Statements of Operations.

We have various tax years under examination by tax authorities in the U.S., in various countries, and in various states, such as New York, in which we have significant business operations. It is not yet known whether these examinations will, in the aggregate, result in our paying additional taxes. We believe our tax reserves are adequate in relation to the potential for additional assessments in each of the jurisdictions in which we are subject to taxation. We regularly assess the likelihood of additional tax assessments in those jurisdictions and, if necessary, adjust our reserves as additional information or events require.

With respect to all tax years open to examination by U.S. federal, various state and local, and non-U.S. tax authorities, we currently anticipate that total unrecognized tax benefits will decrease by an amount between $25.0 and $35.0 in the next twelve months, a portion of which will affect our effective income tax rate, primarily as a result of the settlement of tax examinations and the lapsing of statutes of limitations. This net decrease is related to various items of income and expense, primarily transfer pricing adjustments.

We are effectively settled with respect to U.S. income tax audits for 2010 and years prior to 2009. With limited exceptions, we are no longer subject to state and local income tax audits for years prior to 2004, or non-U.S. income tax audits for years prior to 2006.

Restructuring and Other Reorganization-Related Charges (Reversals), net (Notes)

12 Months Ended

Dec. 31, 2015

Restructuring [Abstract]

Restructuring and Related Activities Disclosure [Text Block]

Restructuring and Other Reorganization-Related (Reversals) Charges, net

The components of restructuring and other reorganization-related (reversals) charges, net for all of our restructuring plans are listed below.



	Years ended December 31,
	2015			2014		2013
Severance and termination costs	$	0.0		$	0.1	$	55.9
Lease termination costs	(0.7		)	0.1		4.2
Other exit costs	(0.1		)	0.0		0.5
Total restructuring and other reorganization-related (reversals) charges, net	$	(0.8	)	$	0.2	$	60.6

2013 Restructuring Plan

In the fourth quarter of 2013, we implemented a cost savings initiative (the "2013 Plan") to better align our cost structure with our revenue, primarily in Continental Europe. In connection with this initiative, we identified and initiated restructuring actions resulting in pre-tax charges in 2013 of $61.2 related to the 2013 Plan, comprised of severance and termination costs of $55.9, lease termination costs of $4.8 and other exit costs of $0.5. In 2015, we recorded an additional $0.1 of net restructuring reversals related to the 2013 Plan at IAN. All restructuring actions were substantially completed by the end of the first quarter of 2014, with remaining payments expected to be made through 2021.

A summary of the 2013 Plan restructuring liability activity is listed below.



	December 31, 2014		Net Restructuring Reversals			Cash Payments			Foreign Currency Translation Adjustment			December 31, 2015
Severance and termination costs	$	4.4	$	0.0		$	(2.1	)	$	(0.2	)	$	2.1
Lease termination costs	2.6		(0.1		)	(1.0		)	(0.1		)	1.4
Total	$	7.0	$	(0.1	)	$	(3.1	)	$	(0.3	)	$	3.5

Accumulated Other Comprehensive Loss, net of tax (Notes)

12 Months Ended

Dec. 31, 2015

Accumulated Other Comprehensive Loss [Abstract]

Comprehensive Income (Loss) Note

Note 9: Accumulated Other Comprehensive Loss, Net of Tax

The following table presents the changes in accumulated other comprehensive loss, net of tax by component.



	Foreign Currency Translation Adjustments			Available-for-Sale Securities			Derivative Instruments			Defined Benefit Pension and Other Postretirement Plans			Total
Balance as of December 31, 2013	$	(243.7	)	$	0.4		$	(11.7	)	$	(156.2	)	$	(411.2	)
Other comprehensive (loss) income before reclassifications	(191.7		)	0.7			(0.6		)	(55.0		)	(246.6		)
Amount reclassified from accumulated other comprehensive loss, net of tax	(0.9		)	(0.3		)	1.4			20.9			21.1
Balance as of December 31, 2014	$	(436.3	)	$	0.8		$	(10.9	)	$	(190.3	)	$	(636.7	)
Other comprehensive (loss) income before reclassifications	(252.6		)	0.5			0.0			14.6			(237.5		)
Amount reclassified from accumulated other comprehensive loss, net of tax	23.3			0.0			1.3			4.0			28.6
Balance as of December 31, 2015	$	(665.6	)	$	1.3		$	(9.6	)	$	(171.7	)	$	(845.6	)

Amounts reclassified from accumulated other comprehensive loss, net of tax for the years ended December 31, 2015, 2014 and 2013 are as follows:



	Years ended December 31,									Affected Line Item in the Consolidated Statements of Operations
	2015			2014			2013
Foreign currency translation adjustments	$	23.3		$	(0.9	)	$	0.0		Other (expense) income, net
Gains on available-for-sale securities	0.0			0.0			(1.4		)	Other (expense) income, net
Losses on derivative instruments	2.0			1.9			1.7			Interest expense
Amortization of defined benefit pension and postretirement plans items ¹	10.4			10.5			10.8
Tax effect	(7.1		)	9.6			(2.4		)	Provision for income taxes
Total amount reclassified from accumulated other comprehensive loss, net of tax	$	28.6		$	21.1		$	8.7


1	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 12 for further information.

- Definition

The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e689-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 220
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 220
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-Paragraph 11
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Reclassification Adjustments
-URI http://asc.fasb.org/extlink&oid=6522872

+ Details

Incentive Compensation Plans (Notes)

12 Months Ended

Dec. 31, 2015

Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]

Incentive Compensation Plans

2014 Performance Incentive Plan

We issue stock-based compensation and cash awards to our employees under a plan established by the Compensation and Leadership Talent Committee of the Board of Directors (the “Compensation Committee”) and approved by our shareholders. In May 2014, our shareholders approved the 2014 Performance Incentive Plan (the “2014 PIP”), replacing the 2009 Performance Incentive Plan (the “2009 PIP”) and previous incentive plans. The number of shares of common stock initially available for grants of all equity awards under the 2014 PIP is 28.8. Pursuant to the terms of the 2014 PIP, the number of shares that may be awarded to any one participant for each type of award is limited to 2.0. The vesting period of awards granted is generally commensurate with the requisite service period. We generally issue new shares to satisfy the exercise of stock options or the distribution of other stock-based awards.

Additionally, under the 2014 PIP, we have the ability to issue performance cash awards. Performance cash awards are granted to certain employees who otherwise would have been eligible to receive performance-based stock awards. These awards have a service period vesting condition and a performance vesting condition. The amount of the performance cash award received by an employee with a performance vesting condition can range from 0% to 300% of the target amount of the original grant value. Performance cash awards generally vest in three years. The Compensation Committee may grant performance cash awards to any eligible employee; however, no employee can receive more than $10.0 during a performance period.

The amounts of stock-based compensation expense as reflected in salaries and related expenses in our Consolidated Statements of Operations, and the related tax benefit, are listed below.



	Years ended December 31,
	2015		2014		2013
Stock options	$	1.0	$	2.1	$	3.7
Stock-settled awards	11.6		10.0		9.8
Cash-settled awards	0.7		0.6		1.5
Performance-based awards	57.7		42.2		29.6
Employee stock purchase plan	0.7		0.6		0.6
Other ¹	0.9		1.2		0.8
Stock-based compensation expense	$	72.6	$	56.7	$	46.0
Tax benefit	$	26.3	$	20.6	$	17.6


1	Represents charges recorded for severance expense related to stock-based compensation awards.

Stock Options

Stock options are granted with the exercise price equal to the fair market value of our common stock on the grant date. They are generally first exercisable between two and four years from the grant date and expire ten years from the grant date (or earlier in the case of certain terminations of employment).

The following tables are a summary of stock option activity during 2015.



	Options		Weighted- Average Exercise Price (per option)		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Stock options outstanding as of January 1, 2015	7.4		$	9.70
Exercised	(1.4	)	9.99
Stock options outstanding as of December 31, 2015	6.0		$	9.63	3.5	$	82.4
Stock options vested and expected to vest as of December 31, 2015	6.0		$	9.63	3.5	$	82.4
Stock options exercisable as of December 31, 2015	5.8		$	9.51	3.4	$	80.1

	Options		Weighted- Average Grant Date Fair Value (per option)		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Non-vested as of January 1, 2015	0.6		$	4.16
Vested	(0.4	)	4.18
Non-vested as of December 31, 2015	0.2		$	4.14	7.2	$	2.4

There were 1.4, 1.7 and 5.2 stock options exercised in 2015, 2014 and 2013, respectively. The total intrinsic value of stock options exercised during 2015, 2014 and 2013 was $16.1, $10.7 and $26.2, respectively. The cash received from the stock options exercised in 2015, 2014 and 2013 was $20.4, $25.2 and $59.5, respectively.

We use the Black-Scholes option-pricing model to estimate the fair value of options granted, which requires the input of subjective assumptions including the option’s expected term and the price volatility of the underlying stock. Changes in the assumptions can materially affect the estimate of fair value, and our results of operations could be materially impacted. There were no stock options granted during the years ended December 31, 2015 and 2014. The weighted-average grant-date fair value per option during the year ended December 31, 2013 was $4.14.

The fair value of each option grant has been estimated with the following weighted-average assumptions.



	Year ended December 31, 2013
Expected volatility ¹	40.2	%
Expected term (years) ²	6.9
Risk-free interest rate ³	1.3	%
Expected dividend yield ⁴	2.4	%


1	The expected volatility used to estimate the fair value of stock options awarded is based on a blend of: (i) historical volatility of our common stock for periods equal to the expected term of our stock options and (ii) implied volatility of tradable forward put and call options to purchase and sell shares of our common stock.

The estimate of our expected term is based on the average of: (i) an assumption that all outstanding options are exercised upon achieving their full vesting date and (ii) an assumption that all outstanding options will be exercised at the midpoint between the current date (i.e., the date awards have ratably vested through) and their full contractual term. In determining the estimate, we considered several factors, including the historical option exercise behavior of our employees and the terms and vesting periods of the options.


3	The risk-free interest rate is determined using the implied yield currently available for zero-coupon U.S. government issuers with a remaining term equal to the expected term of the options.


4	The expected dividend yield was calculated based on an annualized dividend of $0.30 per share in 2013.

Stock-Based Compensation

We grant other stock-based compensation awards such as stock-settled awards, cash-settled awards and performance-based awards (settled in cash or shares) to certain key employees. The number of shares or units received by an employee for performance-based awards depends on Company performance against specific performance targets and could range from 0% to 300% of the target amount of shares originally granted. Incentive awards are subject to certain restrictions and vesting requirements as determined by the Compensation Committee. The fair value of the shares on the grant date is amortized over the vesting period, which is generally three years. Upon completion of the vesting period for cash-settled awards, the grantee is entitled to receive a payment in cash based on the fair market value of the corresponding number of shares of common stock. No monetary consideration is paid by a recipient for any incentive award. The fair value of cash-settled awards is adjusted each quarter based on our share price. The holders of stock-settled awards have absolute ownership interest in the underlying shares of common stock prior to vesting, which includes the right to vote and receive dividends. Dividends declared on common stock are accrued during the vesting period and paid when the award vests. The holders of cash-settled and performance-based awards have no ownership interest in the underlying shares of common stock until the awards vest and the shares of common stock are issued.

Stock-based compensation awards expected to be settled in cash have been classified as liabilities in our Consolidated Balance Sheets as of December 31, 2015 and 2014.



	Years ended December 31,
	2015		2014		2013
Stock-Settled Awards:
Awards granted	0.8		1.2		1.1
Weighted-average grant-date fair value (per award)	$	22.07	$	17.77	$	13.51
Total fair value of vested awards distributed	$	18.8	$	12.6	$	35.4
Cash-Settled Awards:
Awards granted	0.1		0.1		0.1
Weighted-average grant-date fair value (per award)	$	20.46	$	18.20	$	16.35
Total fair value of vested awards distributed	$	0.2	$	0.6	$	5.4
Performance-Based Awards:
Awards granted	2.9		3.5		1.5
Weighted-average grant-date fair value (per award)	$	20.88	$	16.56	$	11.97
Total fair value of vested awards distributed	$	18.7	$	15.3	$	0.2

In conjunction with common stock dividends declared in 2015 and 2014, we accrued dividends of $0.9 and $0.8, respectively, on non-vested stock-settled awards and paid dividends of $0.6 and $0.5 for stock-settled awards that vested during 2015 and 2014, respectively.

A summary of the activity of our non-vested stock-settled awards, cash-settled awards and performance-based awards during 2015 is presented below (performance-based awards are shown at 100% of the shares originally granted).



	Stock-Settled Awards					Cash-Settled Awards					Performance-Based Awards
	Awards			Weighted- Average Grant-Date Fair Value (per award)		Awards			Weighted- Average Grant-Date Fair Value (per award)		Awards			Weighted- Average Grant-Date Fair Value (per award)
Non-vested as of January 1, 2015	2.2			$	15.47	0.1			$	16.99	5.8			$	14.39
Granted	0.8			22.07		0.1			20.46		2.9			20.88
Vested	(0.9		)	14.10		(0.1		)	11.99		(0.8		)	11.09
Forfeited	(0.1		)	17.92		0.0			0.00		(0.8		)	13.36
Non-vested as of December 31, 2015	2.0			$	18.53	0.1			$	18.75	7.1			$	17.50
Total unrecognized compensation expense remaining	$	16.2				$	1.8				$	87.1
Weighted-average years expected to be recognized over	1.3					1.7					1.8

During 2015, 2014 and 2013, additional performance cash awards with a total target value of $1.2, $2.9 and $35.6, respectively, were awarded under the 2014 PIP and 2009 PIP and will be settled in shares upon vesting, which is three years from the grant date. The total fair value of the vested awards distributed during the years ended December 31, 2015 and 2014 was $16.6 and $19.8, respectively. As of December 31, 2015, there was $1.6 of total unrecognized compensation expense related to these awards, which is expected to be recognized over a remaining weighted-average period of 0.2 years.

In conjunction with our annual grant of long-term incentive compensation awards, we reviewed our estimates and assumptions in 2015, which resulted in a forfeiture rate consistent with prior years.

2009 Restricted Cash Plan

In March 2009, the Compensation Committee approved the Interpublic Restricted Cash Plan (the “Cash Plan”). Under the Cash Plan, the Board, the Compensation Committee or the Plan Administrator may grant cash awards to certain employees eligible to receive stock-settled and cash-settled awards. Cash awards, when granted, have a service period vesting condition and generally vest in three years.

Cash Awards

During the years ended December 31, 2015, 2014 and 2013, the Compensation Committee granted cash awards under the Cash Plan with a total target value of $1.3, $5.8 and $4.6, respectively, and we recognized $3.0, $3.1 and $4.0, respectively, in salaries and related expenses in our Consolidated Statements of Operations.

During the years ended December 31, 2015, 2014 and 2013, the Compensation Committee granted performance awards to be settled in cash under the 2014 PIP and 2009 PIP with a total target value of $31.8, $33.0, and $47.4, respectively, and we recognized $35.8, $27.3 and $18.3, respectively, in salaries and related expenses in our Consolidated Statements of Operations.

We amortize the present value of the amount expected to vest for cash awards and performance cash awards over the vesting period using the straight-line method, less an assumed forfeiture rate. Cash awards do not fall within the scope of the authoritative guidance for stock compensation as they are not paid in equity and the value of the award is not correlated with our stock price. Due to the cash nature of the payouts and the vesting period, we account for these awards in accordance with authoritative guidance for deferred compensation arrangements.

Employee Stock Purchase Plans

In December 2015, the Board approved The Interpublic Group of Companies Employee Stock Purchase Plan (2016) (the “New ESPP”), replacing the prior employee stock purchase plan under which, prior to its expiration on December 31, 2015, 3.0 shares were issued. The issuance of shares under the New ESPP is subject to shareholder approval of the plan at the Company’s 2016 Annual Meeting of Shareholders. Subject to receiving shareholder approval, under the New ESPP eligible employees may purchase our common stock through payroll deductions not exceeding 10% of their eligible compensation or 900 (actual number) shares each offering period, consistent with the prior employee stock purchase plan. The price an employee pays for a share of common stock under the New ESPP continues to be 90% of the lesser of the average market price of a share on the first business day of the offering period or the average market price of a share on the last business day of the offering period of three months. An aggregate of 10.0 shares are reserved for issuance under the New ESPP.

Fair Value Measurements (Notes)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value Disclosures

Fair Value Measurements

Authoritative guidance for fair value measurements establishes a fair value hierarchy which requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value:



Level 1		Unadjusted quoted prices in active markets for identical assets or liabilities. An active market for the asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2		Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3		Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Financial Instruments that are Measured at Fair Value on a Recurring Basis

We primarily apply the market approach to determine the fair value of financial instruments that are measured at fair value on a recurring basis. There were no changes to our valuation techniques used to determine the fair value of financial instruments during 2015 as compared to the prior year.

The following tables present information about our financial instruments measured at fair value on a recurring basis as of December 31, 2015 and 2014, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.



	December 31, 2015												Balance Sheet Classification
	Level 1			Level 2			Level 3			Total			Balance Sheet Classification
Assets
Cash equivalents	$	875.7		$	0.0		$	0.0		$	875.7		Cash and cash equivalents
Short-term marketable securities	6.8			0.0			0.0			6.8			Marketable securities
Long-term investments	0.4			0.0			0.0			0.4			Other assets
Total	$	882.9		$	0.0		$	0.0		$	882.9

As a percentage of total assets	7.0		%	0.0		%	0.0		%	7.0		%

Liabilities
Mandatorily redeemable noncontrolling interests ¹	$	0.0		$	0.0		$	45.0		$	45.0

	December 31, 2014												Balance Sheet Classification
	Level 1			Level 2			Level 3			Total			Balance Sheet Classification
Assets
Cash equivalents	$	901.4		$	0.0		$	0.0		$	901.4		Cash and cash equivalents
Short-term marketable securities	6.6			0.0			0.0			6.6			Marketable securities
Long-term investments	0.5			0.0			0.0			0.5			Other assets
Total	$	908.5		$	0.0		$	0.0		$	908.5

As a percentage of total assets	7.1		%	0.0		%	0.0		%	7.1		%

Liabilities
Mandatorily redeemable noncontrolling interests ¹	$	0.0		$	0.0		$	32.8		$	32.8

Relates to unconditional obligations to purchase additional noncontrolling equity shares of consolidated subsidiaries. Fair value measurement of the obligation was based upon the amount payable as if the forward contracts were settled. The amount redeemable within the next twelve months is classified in accrued liabilities; any interests redeemable thereafter are classified in other non-current liabilities.

The following table presents additional information about financial instruments measured at fair value on a recurring basis and for which we utilize Level 3 inputs to determine fair value.



	Years ended December 31,
Liabilities	2015			2014
Mandatorily redeemable noncontrolling interests - Balance at beginning of period	$	32.8		$	27.0
Level 3 additions	23.7			5.6
Level 3 reductions	(17.2		)	(0.8		)
Realized losses included in net income	5.3			1.0
Foreign currency translation	0.4			0.0
Mandatorily redeemable noncontrolling interests - Balance at end of period	$	45.0		$	32.8

Level 3 reductions primarily consist of cash payments made related to unconditional obligations to purchase additional equity interests in previous acquisitions, which are classified within the financing section of our Consolidated Statements of Cash Flows. Level 3 additions relate to new unconditional obligations to purchase additional equity interests in previous acquisitions for cash in future periods. Realized losses included in net income for mandatorily redeemable noncontrolling interests are reported as a component of interest expense in our Consolidated Statements of Operations.

Gross unrealized and realized gains and losses for our long-term investments and short-term marketable securities were not material for the years ended December 31, 2015, 2014 and 2013.

Financial Instruments that are not Measured at Fair Value on a Recurring Basis

The following table presents information about our financial instruments that are not measured at fair value on a recurring basis as of December 31, 2015, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.



	December 31, 2015
	Level 1		Level 2		Level 3		Total
Total long-term debt	$	0.0	$	1,531.4	$	75.2	$	1,606.6

Our long-term debt is comprised of senior notes and other notes payable. The fair value of our senior notes traded over-the-counter is based on quoted prices for such securities, but for which fair value can also be derived from inputs that are readily observable. Therefore, these senior notes are classified as Level 2 within the fair value hierarchy. Our other notes payable are not actively traded, and their fair value is not solely derived from readily observable inputs. The fair value of our other notes payable is determined based on a discounted cash flow model and other proprietary valuation methods, and therefore is classified as Level 3 within the fair value hierarchy. See Note 2 for further information on our long-term debt.

Non-financial Instruments that are Measured at Fair Value on a Recurring Basis

Certain non-financial instruments are measured at fair value on a recurring basis, primarily accrued restructuring charges. Accrued restructuring charges were $3.9 and $8.1 for the years ended December 31, 2015 and 2014, respectively. These charges were valued using our internal estimates based upon a discounted cash flow model and are classified as Level 3 in the fair value hierarchy.

Non-financial Instruments that are Measured at Fair Value on a Nonrecurring Basis

Certain non-financial instruments are measured at fair value on a nonrecurring basis, primarily goodwill, intangible assets, and property and equipment. Accordingly, these assets are not measured and adjusted to fair value on an ongoing basis but are subject to periodic evaluations for potential impairment.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Employee Benefits (Notes)

12 Months Ended

Dec. 31, 2015

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Employee Benefits

Pension and Postretirement Benefit Plans

We have a defined benefit pension plan covering certain U.S. employees (the “Domestic Pension Plan”) that consists of approximately 3,700 participants and is closed to new participants. We also have numerous funded and unfunded plans outside the U.S. The Interpublic Limited Pension Plan in the U.K. is a defined benefit plan and is our most material foreign pension plan in terms of the benefit obligation and plan assets. Some of our domestic and foreign subsidiaries provide postretirement health benefits and life insurance to eligible employees and, in certain cases, their dependents. The domestic postretirement benefit plan is our most material postretirement benefit plan in terms of the benefit obligation. This plan consists of approximately 1,900 participants, is closed to new participants and is unfunded.

Differences between the aggregate income statement and balance sheet amounts listed in the tables below and the totals reported in our Consolidated Statements of Operations, Consolidated Statements of Comprehensive Income and Consolidated Balance Sheets relate to non-material foreign pension and postretirement benefit plans.

Pension and Postretirement Benefit Obligation

The change in the benefit obligation, the change in plan assets, the funded status and amounts recognized for the Domestic Pension Plan, the significant foreign pension plans and the domestic postretirement benefit plan are listed below.



	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
December 31,	2015			2014			2015			2014			2015			2014
Benefit Obligation
Projected benefit obligation as of January 1	$	146.9		$	133.1		$	589.5		$	569.9		$	39.5		$	37.9
Service cost	0.0			0.0			11.1			10.3			0.0			0.1
Interest cost	0.3			6.2			18.9			23.4			1.5			1.7
Benefits paid	(9.3		)	(10.4		)	(20.9		)	(24.1		)	(5.9		)	(5.6		)
Plan participant contributions	0.0			0.0			0.5			0.6			1.5			1.5
Actuarial (gains) losses	(11.0		)	18.0			(28.0		)	55.7			(2.3		)	4.4
Settlements and curtailments	0.0			0.0			(2.4		)	(4.0		)	0.0			0.0
Foreign currency effect	0.0			0.0			(30.1		)	(42.8		)	0.0			0.0
Other	0.0			0.0			(0.7		)	0.5			(0.4		)	(0.5		)

Projected benefit obligation as of December 31	$	126.9		$	146.9		$	537.9		$	589.5		$	33.9		$	39.5

Fair Value of Plan Assets
Fair value of plan assets as of January 1	$	111.5		$	109.6		$	415.5		$	398.5		$	0.0		$	0.0
Actual return on plan assets	(4.3		)	9.6			4.0			44.7			0.0			0.0
Employer contributions	3.2			2.7			21.6			25.7			4.4			4.1
Plan participant contributions	0.0			0.0			0.5			0.6			1.5			1.5
Benefits paid	(9.3		)	(10.4		)	(20.9		)	(24.1		)	(5.9		)	(5.6		)
Settlements	0.0			0.0			(2.0		)	(4.0		)	0.0			0.0
Foreign currency effect	0.0			0.0			(19.1		)	(25.9		)	0.0			0.0
																0.0
Fair value of plan assets as of December 31	$	101.1		$	111.5		$	399.6		$	415.5		$	0.0		$	0.0

Funded status of the plans at December 31	$	(25.8	)	$	(35.4	)	$	(138.3	)	$	(174.0	)	$	(33.9	)	$	(39.5	)



	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
December 31,	2015			2014			2015			2014			2015			2014
Amounts recognized in Consolidated Balance Sheets
Non-current asset	$	0.0		$	0.0		$	8.8		$	8.3		$	0.0		$	0.0
Current liability	0.0			0.0			(6.4		)	(8.0		)	(3.5		)	(4.0		)
Non-current liability	(25.8		)	(35.4		)	(140.7		)	(174.3		)	(30.4		)	(35.5		)

Net liability recognized	$	(25.8	)	$	(35.4	)	$	(138.3	)	$	(174.0	)	$	(33.9	)	$	(39.5	)

Accumulated benefit obligation	$	126.9		$	146.9		$	518.6		$	566.2

Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	$	49.9		$	56.1		$	137.3		$	161.0		$	0.6		$	2.9
Prior service cost (credit)	0.0			0.0			0.6			1.1			(0.7		)	(0.4		)

Total amount recognized	$	49.9		$	56.1		$	137.9		$	162.1		$	(0.1	)	$	2.5

In 2016, we estimate that we will recognize $7.5 and $3.7 of net actuarial losses from accumulated other comprehensive loss, net into net periodic cost related to our domestic pension plan and significant foreign pension plans, respectively.



	Domestic Pension Plan				Foreign Pension Plans
December 31,	2015		2014		2015		2014
Pension plans with underfunded or unfunded accumulated benefit obligation
Aggregate projected benefit obligation	$	126.9	$	146.9	$	525.9	$	577.1
Aggregate accumulated benefit obligation	126.9		146.9		511.1		559.5
Aggregate fair value of plan assets	101.1		111.5		379.2		395.8

Net Periodic Cost

The components of net periodic benefit cost and key assumptions are listed below.



	Domestic Pension Plan									Foreign Pension Plans									Domestic Postretirement Benefit Plan
Years ended December 31,	2015			2014			2013			2015			2014			2013			2015			2014			2013
Service cost	$	0.0		$	0.0		$	0.0		$	11.1		$	10.3		$	9.9		$	0.0		$	0.1		$	0.1
Interest cost	0.3			6.2			5.5			18.9			23.4			21.7			1.5			1.7			1.6
Expected return on plan assets	(7.6		)	(7.3		)	(7.7		)	(20.6		)	(24.7		)	(19.2		)	0.0			0.0			0.0
Settlement and curtailment (gains) losses	0.0			0.0			0.0			(0.2		)	0.5			(0.1		)	0.0			0.0			0.0
Amortization of:
Prior service cost (credit)	0.0			0.0			0.0			0.1			0.2			0.2			(0.1		)	(0.2		)	(0.1		)
Net actuarial losses	6.5			6.6			7.9			4.1			3.4			2.8			0.0			0.0			0.0
Net periodic cost	$	(0.8	)	$	5.5		$	5.7		$	13.4		$	13.1		$	15.3		$	1.4		$	1.6		$	1.6

Assumptions



	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
Years ended December 31,	2015		2014		2013		2015		2014		2013		2015		2014		2013

Net periodic cost
Discount rate	4.15	%	4.85	%	4.00	%	3.41	%	4.29	%	4.32	%	4.00	%	4.85	%	4.00	%
Rate of compensation increase	N/A		N/A		N/A		2.99	%	3.97	%	3.57	%	N/A		N/A		N/A
Expected return on plan assets	7.00	%	7.00	%	7.00	%	5.01	%	6.18	%	5.24	%	N/A		N/A		N/A

Benefit obligation
Discount rate	4.80	%	4.15	%	4.85	%	3.61	%	3.41	%	4.29	%	4.65	%	4.00	%	4.85	%
Rate of compensation increase	N/A		N/A		N/A		3.25	%	2.98	%	3.97	%	N/A		N/A		N/A

Health care cost trend rate assumed for next year
Initial rate (weighted-average)													7.00	%	7.00	%	7.50	%
Year ultimate rate is reached													2024		2019		2019
Ultimate rate													5.00	%	5.00	%	5.00	%

Discount Rates – At December 31, 2015, 2014 and 2013, we determined our discount rates for our Domestic Pension Plan, foreign pension plans and domestic postretirement benefit plan based on either a bond selection/settlement approach or bond yield curve approach. Using the bond selection/settlement approach, we determine the discount rate by selecting a portfolio of corporate bonds appropriate to provide for the projected benefit payments. Using the bond yield curve approach, we determine the discount rate by matching the plans' cash flows to spot rates developed from a yield curve. Both approaches utilize high-quality AA-rated corporate bonds and the plans' projected cash flows to develop a discounted value of the benefit payments, which is then used to develop a single discount rate. In countries where markets for high-quality long-term AA corporate bonds are not well developed, a portfolio of long-term government bonds is used as a basis to develop hypothetical corporate bond yields, which serve as a basis to derive the discount rate.

Expected Return on Assets – Our expected rate of return is determined at the beginning of each year and considers asset class index returns over various market and economic conditions, current and expected market conditions, risk premiums associated with asset classes and long-term inflation rates. We determine both a short-term and long-term view and then select a long-term rate of return assumption that matches the duration of our liabilities.

Fair Value of Pension Plan Assets

The following table presents the fair value of our domestic and foreign pension plan assets as of December 31, 2015 and 2014, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. See Note 11 for a description of the fair value hierarchy.



	December 31, 2015								December 31, 2014
Asset Class	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Investment funds	$	16.8	$	335.8	$	57.9	$	410.5	$	18.8	$	372.6	$	40.1	$	431.5
Limited partnerships	0.0		0.0		31.0		31.0		0.0		0.0		32.1		32.1
Fixed income securities	22.1		0.4		0.0		22.5		17.6		1.4		0.0		19.0
Insurance contracts	0.0		13.7		0.0		13.7		0.0		19.3		0.0		19.3
Other	23.0		0.0		0.0		23.0		24.8		0.0		0.3		25.1
Total	$	61.9	$	349.9	$	88.9	$	500.7	$	61.2	$	393.3	$	72.5	$	527.0

Investment funds include mutual funds, common/collective trusts, hedge funds and other commingled assets that are invested primarily in equity and fixed income securities. Mutual funds, which are publicly traded, are primarily valued using recently reported sales prices. All other investment funds, which are not publicly traded, are valued based on the net asset value of shares held by the plan at year end, which reflects the fair value of the underlying investments. Limited partnerships are invested primarily in equity and fixed income securities. Fixed income securities include government and investment-grade corporate bonds. Insurance contracts are valued based on the cash surrender value of the contract. Other investments primarily include cash and cash equivalents, equity securities and derivatives.

The following table presents additional information about our domestic and foreign pension plan assets for which we utilize Level 3 inputs to determine fair value.



	Year ended December 31, 2015												Year ended December 31, 2014
	Investment Funds			Limited Partnerships			Other			Total			Investment Funds			Limited Partnerships			Other			Total
Balance at beginning of period	$	40.1		$	32.1		$	0.3		$	72.5		$	25.4		$	36.1		$	0.6		$	62.1
Actual return on assets:
Assets sold during the year	0.0			0.0			0.0			0.0			0.2			0.2			0.0			0.4
Assets still held at year end	(0.7		)	(1.1		)	0.0			(1.8		)	(0.7		)	(0.3		)	(0.3		)	(1.3		)
Net purchases, sales and settlements	18.5			0.0			0.1			18.6			15.2			(3.9		)	0.0			11.3
Transfers in/out of Level 3	0.0			0.0			(0.4		)	(0.4		)	0.0			0.0			0.0			0.0
Balance at end of period	$	57.9		$	31.0		$	0.0		$	88.9		$	40.1		$	32.1		$	0.3		$	72.5

Asset Allocation

The primary investment goal for our plans’ assets is to maximize total asset returns while ensuring the plans’ assets are available to fund the plans’ liabilities as they become due. The plans’ assets in aggregate and at the individual portfolio level are invested so that total portfolio risk exposure and risk-adjusted returns best achieve this objective. The aggregate amount of our own stock held as investment for our domestic and foreign pension funds is considered negligible relative to the total fund assets. As of December 31, 2015, the weighted-average target and actual asset allocations relating to our domestic and foreign pension plans' assets are listed below.



			December 31,
Asset Class	2016 Target Allocation		2015		2014
Equity securities	23	%	22	%	22	%
Fixed income securities	41	%	38	%	46	%
Real estate	8	%	7	%	5	%
Other	28	%	33	%	27	%
Total	100	%	100	%	100	%

Cash Flows

During 2015, we contributed $3.2 and $21.6 of cash to our domestic and foreign pension plans, respectively. For 2016, we expect to contribute approximately $21.0 of cash to our foreign pension plans. We expect to make no contributions to our Domestic Pension Plan in 2016.

The following estimated future benefit payments, which reflect future service, as appropriate, are expected to be paid in the years indicated below.



Years	Domestic Pension Plan		Foreign Pension Plans		Domestic Postretirement Benefit Plan
2016	$	13.1	$	21.1	$	3.9
2017	12.9		23.1		3.8
2018	8.6		24.0		3.7
2019	8.4		24.6		3.5
2020	8.2		22.2		3.3
2021 - 2025	38.7		126.5		13.6

The estimated future payments for our domestic postretirement benefit plan are before any estimated federal subsidies expected to be received under the Medicare Prescription Drug, Improvement and Modernization Act of 2003.

The following federal subsidies are expected to be received in the years indicated below.



Years	Domestic Postretirement Benefit Plan
2016	$	0.4
2017	0.4
2018	0.4
2019	0.4
2020	0.4
2021 - 2025	1.9

Savings Plans

We sponsor defined contribution plans (the “Savings Plans”) that cover substantially all domestic employees. The Savings Plans permit participants to make contributions on a pre-tax and/or after-tax basis and allow participants to choose among various investment alternatives. We match a portion of participant contributions based upon their years of service. Amounts expensed for the Savings Plans for 2015, 2014 and 2013 were $44.5, $43.0 and $37.7, respectively. Expenses include a discretionary Company contribution of $5.8, $5.2 and $4.9 offset by participant forfeitures of $3.8, $3.6 and $3.3 in 2015, 2014 and 2013, respectively. In addition, we maintain defined contribution plans in various foreign countries and contributed $43.9, $42.4 and $36.9 to these plans in 2015, 2014 and 2013, respectively.

Deferred Compensation and Benefit Arrangements

We have deferred compensation arrangements which (i) permit certain of our key officers and employees to defer a portion of their salary or incentive compensation or (ii) require us to contribute an amount to the participant’s account. The arrangements typically provide that the participant will receive the amounts deferred plus interest upon attaining certain conditions, such as completing a certain number of years of service or upon retirement or termination. As of December 31, 2015 and 2014, the deferred compensation liability balance was $95.7 and $97.7, respectively. Amounts expensed for deferred compensation arrangements in 2015, 2014 and 2013 were $6.3, $9.8 and $13.4, respectively.

We have deferred benefit arrangements with certain key officers and employees that provide participants with an annual payment, payable when the participant attains a certain age and after the participant’s employment has terminated. The deferred benefit liability was $141.5 and $153.2 as of December 31, 2015 and 2014, respectively. Amounts expensed for deferred benefit arrangements in 2015, 2014 and 2013 were $9.7, $10.8 and $14.0, respectively.

We have purchased life insurance policies on participants’ lives to assist in the funding of the related deferred compensation and deferred benefit liabilities. As of December 31, 2015 and 2014, the cash surrender value of these policies was $167.0 and $165.6, respectively. In addition to the life insurance policies, certain investments are held for the purpose of paying the deferred compensation and deferred benefit liabilities. These investments, along with the life insurance policies, are held in a separate revocable trust for the purpose of paying the deferred compensation and the deferred benefit arrangement liabilities. As of December 31, 2015 and 2014, the value of such investments in the trust was $10.7 and $8.5, respectively. The short-term investments are included in cash and cash equivalents, and the long-term investments and cash surrender value of the policies are included in other assets.

Long-Term Disability Plan

We have a long-term disability plan which provides income replacement benefits to eligible participants who are unable to perform their job duties or any job related to his or her education, training or experience. As all income replacement benefits are fully insured, no related obligation is required as of December 31, 2015 and 2014. In addition to income replacement benefits, plan participants may remain covered for certain health and life insurance benefits up to normal retirement age, and accordingly, we have recorded an obligation of $8.0 as of December 31, 2015 and 2014.

Segment Information (Notes)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Segment Information

As of December 31, 2015, we have two reportable segments: IAN and CMG. IAN is comprised of McCann Worldgroup, Foote, Cone & Belding ("FCB"), MullenLowe Group, IPG Mediabrands, our digital specialist agencies and our domestic integrated agencies. CMG is comprised of a number of our specialist marketing services offerings. We also report results for the “Corporate and other” group.

Within IAN, our agencies provide a comprehensive array of global communications and marketing services, each offering a distinctive range of solutions for our clients. Our digital specialist agencies provide unique digital capabilities and service their own client rosters while also serving as key digital partners. In addition, our domestic integrated agencies, including Hill Holliday, Carmichael Lynch and Tierney, provide a full range of advertising, marketing communications services and/or marketing services and partner with our global operating divisions as needed. IAN’s operating divisions share similar economic characteristics and are similar in other areas, specifically related to the nature of their services, the manner in which the services are provided and the similarity of their respective customers.

CMG, which includes Weber Shandwick, Cassidy, DeVries, Golin, FutureBrand, Jack Morton and Octagon Worldwide, provides clients with diversified services, including public relations, meeting and event production, sports and entertainment marketing, corporate and brand identity, and strategic marketing consulting. CMG shares some similarities with service lines offered by IAN; however, on an aggregate basis, CMG has a higher proportion of arrangements for which they act as principal, a different distribution model than IAN and different margin structure.

The profitability measure employed by our chief operating decision maker for allocating resources to operating divisions and assessing operating division performance is operating income (loss), excluding the impact of restructuring and other reorganization-related (reversals) charges, net. All segments follow the same accounting policies as those described in Note 1.

Certain corporate and other charges are reported as separate line items within total segment operating income and include corporate office expenses, as well as shared service center expenses and certain other centrally managed expenses that are not fully allocated to operating divisions. Salaries and related expenses include salaries, long-term incentive awards, annual bonuses and other miscellaneous benefits for corporate office employees. Office and general expenses primarily include professional fees related to internal control compliance, financial statement audits and legal, information technology and other consulting services, which are engaged and managed through the corporate office. In addition, office and general expenses includes rental expense and depreciation of leasehold improvements for properties occupied by corporate office employees. A portion of centrally managed expenses are allocated to operating divisions based on a formula that uses the planned revenues of each of the operating units. Amounts allocated also include specific charges for information technology-related projects, which are allocated based on utilization.

Summarized financial information concerning our reportable segments is shown in the following table.



	Years ended December 31,
	2015			2014			2013
Revenue:
IAN	$	6,144.9		$	6,076.3		$	5,772.8
CMG	1,468.9			1,460.8			1,349.5
Total	$	7,613.8		$	7,537.1		$	7,122.3

Segment operating income (loss):
IAN	$	846.6		$	774.7		$	660.0
CMG	166.3			163.4			139.7
Corporate and other	(141.8		)	(149.5		)	(140.8		)
Total	871.1			788.6			658.9

Restructuring and other reorganization-related reversals (charges), net	0.8			(0.2		)	(60.6		)
Interest expense	(85.8		)	(84.9		)	(122.7		)
Interest income	22.8			27.4			24.7
Other expense, net	(46.7		)	(10.2		)	(32.3		)
Income before income taxes	$	762.2		$	720.7		$	468.0

Depreciation and amortization of fixed assets and intangible assets:
IAN	$	117.5		$	124.5		$	125.8
CMG	18.4			18.5			15.8
Corporate and other	21.1			20.0			15.8
Total	$	157.0		$	163.0		$	157.4

Capital expenditures:
IAN	$	117.5		$	92.0		$	108.9
CMG	12.7			11.7			18.6
Corporate and other	30.9			45.0			45.5
Total	$	161.1		$	148.7		$	173.0

	December 31,
	2015			2014
Total assets:
IAN	$	10,738.2		$	11,080.2
CMG	1,338.6			1,347.5
Corporate and other	508.3			308.9
Total	$	12,585.1		$	12,736.6

Revenue and long-lived assets, excluding intangible assets, are presented by major geographic area in the following table.



	Revenue						Long-Lived Assets
	Years ended December 31,						December 31,
	2015		2014		2013		2015		2014
Domestic	$	4,475.5	$	4,184.0	$	3,972.6	$	600.1	$	572.9
International:
United Kingdom	687.7		688.3		568.3		56.3		56.7
Continental Europe	697.2		804.7		800.6		58.6		66.4
Asia Pacific	916.9		922.5		868.9		108.8		102.2
Latin America	383.5		470.4		464.5		45.0		69.2
Other	453.0		467.2		447.4		38.0		32.4
Total International	3,138.3		3,353.1		3,149.7		306.7		326.9
Total Consolidated	$	7,613.8	$	7,537.1	$	7,122.3	$	906.8	$	899.8

Revenue is primarily attributed to geographic areas based on where the services are performed. Property and equipment are allocated based upon physical location. Other assets and investments are allocated based on the location of the related operations.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8981-108599

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8380-108599

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8933-108599

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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8844-108599

Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-Topic 280
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8984-108599

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e9031-108599

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e9054-108599

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=51669610&loc=d3e8906-108599

+ Details

Commitments and Contingencies (Notes)

12 Months Ended

Dec. 31, 2015

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Leases

We lease office premises and equipment. Where leases contain escalation clauses or concessions, such as rent holidays and landlord/tenant incentives or allowances, the impact of such adjustments is recognized on a straight-line basis over the minimum lease period. Certain leases provide for renewal options and require the payment of real estate taxes or other occupancy costs, which are also subject to escalation clauses. Net rent expense is listed in the table below.



	Years ended December 31,
	2015			2014			2013
Gross rent expense	$	336.5		$	357.7		$	366.1
Third-party sublease rental income	(5.5		)	(6.1		)	(16.1		)
Net rent expense	$	331.0		$	351.6		$	350.0

Cash amounts for future minimum lease commitments for office premises and equipment under non-cancelable leases, along with minimum sublease rental income to be received under non-cancelable subleases, are listed in the table below.



Period	Rent Obligations		Sublease Rental Income			Net Rent
2016	$	322.0	$	(4.4	)	$	317.6
2017	300.4		(1.9		)	298.5
2018	272.2		(0.8		)	271.4
2019	246.1		(0.7		)	245.4
2020	224.5		0.0			224.5
Thereafter	909.0		0.0			909.0
Total	$	2,274.2	$	(7.8	)	$	2,266.4

Guarantees

We have guaranteed certain obligations of our subsidiaries relating principally to operating leases and credit facilities of certain subsidiaries. The amount of parent company guarantees on lease obligations was $619.4 and $580.4 as of December 31, 2015 and 2014, respectively, and the amount of parent company guarantees primarily relating to credit facilities was $336.5 and $329.2 as of December 31, 2015 and 2014, respectively. In the event of non-payment by the applicable subsidiary of the obligations covered by a guarantee, we would be obligated to pay the amounts covered by that guarantee. As of December 31, 2015, there were no material assets pledged as security for such parent company guarantees.

Contingent Acquisition Obligations

The following table details the estimated future contingent acquisition obligations payable in cash as of December 31, 2015.



	2016		2017		2018		2019		2020		Thereafter		Total
Deferred acquisition payments	$	53.8	$	39.2	$	13.1	$	13.6	$	7.5	$	3.1	$	130.3
Redeemable noncontrolling interests and call options with affiliates ¹	48.4		70.5		43.0		6.4		5.2		11.9		185.4
Total contingent acquisition payments	102.2		109.7		56.1		20.0		12.7		15.0		315.7
Less: cash compensation expense included above	0.2		0.2		0.1		0.1		0.1		0.0		0.7
Total	$	102.0	$	109.5	$	56.0	$	19.9	$	12.6	$	15.0	$	315.0

We have entered into certain acquisitions that contain both redeemable noncontrolling interests and call options with similar terms and conditions. The estimated amounts listed would be paid in the event of exercise at the earliest exercise date. We have certain redeemable noncontrolling interests that are exercisable at the discretion of the noncontrolling equity owners as of December 31, 2015. These estimated payments of $31.0 are included within the total payments expected to be made in 2016, and will continue to be carried forward into 2017 or beyond until exercised or expired. Redeemable noncontrolling interests are included in the table at current exercise price payable in cash, not at applicable redemption value in accordance with the authoritative guidance for classification and measurement of redeemable securities.

The majority of these payments are contingent upon achieving projected operating performance targets and satisfying other conditions specified in the related agreements and are subject to revision in accordance with the terms of the respective agreements. See Note 4 for further information relating to the payment structure of our acquisitions.

Legal Matters

We are involved in various legal proceedings, and subject to investigations, inspections, audits, inquiries and similar actions by governmental authorities, arising in the normal course of business. The types of allegations that arise in connection with such legal proceedings vary in nature, but can include claims related to contract, employment, tax and intellectual property matters. We evaluate all cases each reporting period and record liabilities for losses from legal proceedings when we determine that it is probable that the outcome in a legal proceeding will be unfavorable and the amount, or potential range, of loss can be reasonably estimated. In certain cases, we cannot reasonably estimate the potential loss because, for example, the litigation is in its early stages. While any outcome related to litigation or such governmental proceedings in which we are involved cannot be predicted with certainty, management believes that the outcome of these matters, individually and in the aggregate, will not have a material adverse effect on our financial condition, results of operations or cash flows.

As previously disclosed, on April 10, 2015, a federal judge in Brazil authorized the search of the records of an agency's offices in São Paulo and Brasilia, in connection with an ongoing investigation by Brazilian authorities involving payments potentially connected to local government contracts. The Company had previously investigated the matter and taken a number of remedial and disciplinary actions. The Company is in the process of concluding a settlement related to these matters with government agencies and has provided for such settlement in its Consolidated Financial Statements.

Recent Accounting Standards (Notes)	12 Months Ended
Recent Accounting Standards (Notes)	Dec. 31, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Standards	Recent Accounting Standards Fair Value Measurements In January 2016, the Financial Accounting Standards Board (the “FASB”) issued amended guidance which updates the fair value presentation requirements for certain financial instruments. Equity investments with readily determinable fair values, other than those accounted for using the equity method of accounting, must now be measured at fair value with changes recorded through current earnings rather than other comprehensive income. This amended guidance will be effective for us beginning January 1, 2018, at which time a cumulative-effect adjustment may be recorded on our Consolidated Balance Sheets. We do not expect the adoption of this amended guidance to have a significant impact on our consolidated Financial Statements. Deferred Income Taxes In November 2015, the FASB issued amended guidance which requires all deferred income tax assets and liabilities to be presented as noncurrent on the balance sheet. This amended guidance is effective beginning January 1, 2017, and may be applied retrospectively or prospectively, with early adoption permitted. We have early adopted this amended guidance and applied the presentation prospectively as of December 31, 2015. The adoption did not have a significant impact on our Consolidated Financial Statements. See Note 7 to the Consolidated Financial Statements for additional information related to the adoption of this amended guidance. Business Combinations In September 2015, the FASB issued amended guidance which requires measurement period adjustments to be recorded in the reporting period in which the adjustment amounts are determined. Previously, such adjustments were required to be retrospectively recorded in prior period financial information. This amended guidance is effective beginning January 1, 2016, and applied prospectively, with early adoption permitted. We have early adopted this amended guidance as of the quarter ended September 30, 2015, and the adoption did not have a significant impact on our Consolidated Financial Statements. Revenue Recognition In May 2014, the FASB issued amended guidance on revenue recognition which requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard affects the timing of recognizing revenue in connection with variable consideration. In July 2015, the FASB affirmed its proposal to delay the effective date of the new revenue standard by one year to January 1, 2018, with early adoption to be permitted as of the original effective date of January 1, 2017. We are currently assessing the impact the adoption of the amended guidance will have on our Consolidated Financial Statements. Debt Issuance Costs In April 2015, the FASB issued amended guidance which requires debt issuance costs to be presented as a direct deduction from the carrying value of the associated debt liability rather than as separate assets on the balance sheet. The FASB later issued guidance in August 2015 stating that debt issuance costs related to line-of-credit arrangements may be presented as an asset and subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The recognition and measurement guidance for debt issuance costs are not affected by this amendment. This amended guidance, which is effective beginning January 1, 2016, requires retrospective application, with early adoption permitted. We have early adopted this amended guidance as of the year ended December 31, 2015, and the adoption did not have a significant impact on our Consolidated Financial Statements. See Note 2 to the Consolidated Financial Statements for additional information related to the adoption of this amended guidance. Consolidation In February 2015, the FASB issued amended guidance to the consolidation standard which updates the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The amendment modifies the evaluation of whether limited partnerships and similar legal entities are variable interest entities (“VIEs”) or voting interest entities and affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships, among other provisions. This amended guidance will be effective for us beginning January 1, 2016. We do not expect the adoption of this amended guidance to have a significant impact on our Consolidated Financial Statements. Extraordinary and Unusual Items In January 2015, the FASB issued amended guidance which eliminates the concept of extraordinary items from generally accepted accounting principles. Prior to this amendment, an entity was required to separately classify and present an event or transaction that was determined to be both unusual in nature and infrequent in occurrence as an extraordinary item, net of tax, after income from continuing operations in the income statement. Upon adopting this amended guidance, a material event or transaction that an entity considers to be unusual or infrequent, or both, may still be presented separately but will now be presented on a pre-tax basis within income from continuing operations or disclosed in the notes to the financial statements. This amended guidance is effective beginning January 1, 2016 and may be applied retrospectively or prospectively, with early adoption permitted. We have early adopted this amended guidance and applied the presentation prospectively as of the quarter ended March 31, 2015. The adoption did not have a significant impact on our Consolidated Financial Statements. Going Concern In August 2014, the FASB issued amended guidance which defines management's responsibility to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern and to provide related disclosures. Currently, this evaluation has only been an auditor requirement. Specifically, the amendments (1) provide a definition of the term “substantial doubt,” (2) require an evaluation every reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of the consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that financial statements are issued. This amended guidance is effective beginning January 1, 2016. We do not expect the adoption of this amended guidance to have a significant impact on our Consolidated Financial Statements.

- Definition

Tabular disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Glossary Direct Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6510796

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Indirect Effects of a Change in Accounting Principle
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Results by Quarter (Unaudited) (Notes)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information

Results by Quarter (Unaudited)



	Three Months Ended March 31,						Three Months Ended June 30,						Three Months Ended September 30,						Three Months Ended December 31,
	2015			2014			2015			2014			2015			2014			2015			2014
Revenue	$	1,676.0		$	1,637.5		$	1,876.1		$	1,851.4		$	1,865.5		$	1,841.1		$	2,196.2		$	2,207.1
Salaries and related expenses	1,215.2			1,188.6			1,205.2			1,170.2			1,202.2			1,195.2			1,235.1			1,266.4
Office and general expenses	453.1			461.1			455.1			484.7			472.1			474.7			504.7			507.6
Restructuring and other reorganization-related (reversals) charges, net	(0.1		)	(0.5		)	0.0			0.7			(0.7		)	(0.1		)	0.0			0.1
Operating income (loss)	7.8			(11.7		)	215.8			195.8			191.9			171.3			456.4			433.0
Other income (expense), net ¹	0.3			1.7			0.5			(11.2		)	(37.2		)	(0.6		)	(10.3		)	(0.1		)
Total (expenses) and other income¹	(13.4		)	(12.3		)	(14.8		)	(27.2		)	(52.9		)	(13.8		)	(28.6		)	(14.4		)
(Benefit of) provision for income taxes ²	(1.4		)	(1.7		)	77.7			65.3			61.1			65.0			145.4			87.9
Net (loss) income	(4.2		)	(22.4		)	123.8			103.7			78.0			92.8			282.9			331.3
Net (loss) income available to IPG common stockholders ²	$	(1.8	)	$	(20.9	)	$	121.2		$	99.4		$	74.9		$	89.7		$	260.3		$	308.9
(Loss) earnings per share available to IPG common stockholders:
Basic	$	0.00		$	(0.05	)	$	0.30		$	0.24		$	0.18		$	0.21		$	0.65		$	0.75
Diluted	$	0.00		$	(0.05	)	$	0.29		$	0.23		$	0.18		$	0.21		$	0.63		$	0.73

Dividends declared per common stock	$	0.120		$	0.095		$	0.120		$	0.095		$	0.120		$	0.095		$	0.120		$	0.095


1	The three months ended December 31, 2015 included pre-tax losses of $12.0 on sales of businesses. The three months ended September 30, 2015 included pre-tax losses of $38.0 on sales of businesses. The three months ended June 30, 2014 included a pre-tax loss of $10.4 related to our early extinguishment of debt.


2	The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.

Subsequent Events (Notes)	12 Months Ended
Subsequent Events (Notes)	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events In February 2016, we announced that our Board had approved a new share repurchase program to repurchase from time to time up to $300.0, excluding fees, of our common stock (the "2016 Share Repurchase Program"). The authorization for repurchases under the 2016 Share Repurchase Program is in addition to any amounts remaining for repurchase under the 2015 Share Repurchase Program. See Note 5 for further information on the 2015 Share Repurchase Program. There is no expiration date associated with the share repurchase programs. We may effect such repurchases through open market purchases, trading plans established in accordance with SEC rules, derivative transactions or other means. We expect to continue to repurchase our common stock in future periods, although the timing and amount of the repurchases will depend on market conditions and other funding requirements. We also announced in February 2016 that our Board had declared a common stock cash dividend of $0.15 per share, payable on March 15, 2016 to holders of record as of the close of business on March 1, 2016.

Significant Accounting Policies Principles of Consolidation (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements include the accounts of the Company and its consolidated subsidiaries, some of which are not wholly owned. Investments in companies over which we do not have control, but have the ability to exercise significant influence, are accounted for using the equity method of accounting. Investments in companies over which we have neither control nor have the ability to exercise significant influence are accounted for under the cost method. All intercompany accounts and transactions have been eliminated in consolidation. We have consolidated certain entities meeting the definition of variable interest entities, and the inclusion of these entities does not have a material impact on our Consolidated Financial Statements.

Significant Accounting Policies Use of Estimates (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires us to make judgments, assumptions and estimates that affect the amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the reporting date and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and assumptions.

Significant Accounting Policies Revenue Recognition (Policies)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Revenue Recognition

•


•	Fees are recognized on a straight-line or monthly basis when service is provided essentially on a pro-rata basis and the terms of the contract support monthly basis accounting.

•

- Definition

Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.

+ References + Details

Significant Accounting Policies Cash and Cash Equivalents (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents are highly liquid investments, which include certificates of deposit, government securities, commercial paper and time deposits with original maturities of three months or less at the time of purchase and are stated at estimated fair value, which approximates cost. Cash is maintained at multiple high-credit-quality financial institutions.

- Definition

Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value.

+ References + Details

Significant Accounting Policies Short-Term Marketable Securities (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Short-Term Marketable Securities	Short-Term Marketable Securities Short-term marketable securities include investment-grade time deposits, commercial paper and government securities with maturities greater than three months but less than twelve months. These securities are classified as available-for-sale and are carried at fair value with net unrealized gains and losses reported as a component of accumulated other comprehensive loss, which is a component of stockholders’ equity. The cost of securities is determined based upon the average cost of the securities sold.

Significant Accounting Policies Allowance for Doubtful Accounts (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The allowance for doubtful accounts is estimated based on the aging of accounts receivable, reviews of client credit reports, industry trends and economic indicators, as well as reviews of recent payment history for specific customers. The estimate is based largely on a formula-driven calculation but is supplemented with economic indicators and knowledge of potential write-offs of specific client accounts.

Significant Accounting Policies Expenditures Billable to Clients (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Expenditures Billable to Clients	Expenditures Billable to Clients Expenditures billable to clients are primarily comprised of production and media costs that have been incurred but have not yet been billed to clients, as well as fees that have been earned which have not yet been billed to clients. Unbilled amounts are presented in expenditures billable to clients regardless of whether they relate to our fees or production and media costs. A provision is made for unrecoverable costs as deemed appropriate.

- Definition

Disclosure of accounting policy for major classes of inventories, bases of stating inventories (for example, lower of cost or market), methods by which amounts are added and removed from inventory classes (for example, FIFO, LIFO, or average cost), loss recognition on impairment of inventories, and situations in which inventories are stated above cost. If inventory is carried at cost, this disclosure includes the nature of the cost elements included in inventory.

+ References + Details

Significant Accounting Policies Investments (Policies)	12 Months Ended
Significant Accounting Policies Investments (Policies)	Dec. 31, 2015
Accounting Policies [Abstract]
Investments	Investments Our investments in publicly traded companies over which we do not exert a significant influence are classified as available-for-sale. These investments are reported at fair value based on quoted market prices with net unrealized gains and losses reported as a component of accumulated other comprehensive loss. Our non-publicly traded investments and all other publicly traded investments, including investments to fund certain deferred compensation and retirement obligations, are accounted for using the equity method or cost method. We do not disclose the fair value for equity method investments or investments held at cost as it is not practical to estimate fair value since there is no readily available market data and it is cost prohibitive to obtain independent valuations. We regularly review our equity and cost method investments to determine whether a significant event or change in circumstances has occurred that may impact the fair value of each investment. In the event a decline in fair value of an investment occurs, we determine if the decline has been other-than-temporary. We consider our investments strategic and long-term in nature, so we determine if the fair value decline is recoverable within a reasonable period. For our investments, we evaluate fair value based on specific information (valuation methodologies, estimates of appraisals, financial statements, etc.) in addition to quoted market price, if available. We consider all known quantitative and qualitative factors in determining if an other-than-temporary decline in value of an investment has occurred.

- Definition

Disclosure of accounting policy for investments in financial assets, including marketable securities (debt and equity securities with readily determinable fair values), investments accounted for under the equity method and cost method, securities borrowed and loaned, and repurchase and resale agreements. For marketable securities, the disclosure may include the entity's accounting treatment for transfers between investment categories and how the fair values for such securities are determined. Also, for all investments, an entity may describe its policy for assessing, recognizing and measuring impairment of the investment.

+ References + Details

Significant Accounting Policies Derivatives (Policies)	12 Months Ended
Significant Accounting Policies Derivatives (Policies)	Dec. 31, 2015
Accounting Policies [Abstract]
Derivatives	Derivatives We are exposed to market risk related to interest rates, foreign currency rates and certain balance sheet items. From time to time we enter into derivative instruments for risk management purposes, and not for speculative purposes. All derivative instruments are recorded at fair value on our balance sheet. Changes in fair value are immediately included in earnings if the derivatives are not designated as a hedge instrument or if the derivatives do not qualify as effective hedges. For derivatives designated as hedge instruments, we evaluate for hedge accounting both at inception and throughout the hedge period. If a derivative is designated as a fair value hedge, then changes in the fair value of the derivative are offset against the changes in the fair value of the underlying hedged item. If a derivative is designated as a cash flow hedge, then the effective portion of the changes in the fair value of the derivative is recognized as a component of accumulated other comprehensive income and subsequently reclassified to earnings in our Consolidated Statement of Operations in the same period as the underlying hedged transaction affects earnings.

Significant Accounting Policies Property and Equipment (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Property and Equipment	Furniture, equipment, leasehold improvements and buildings are stated at cost, net of accumulated depreciation. Furniture and equipment are depreciated generally using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years for furniture and equipment, 10 to 35 years for buildings and the shorter of the useful life or the remaining lease term for leasehold improvements. Land is stated at cost and is not depreciated. We capitalize certain internal and external costs incurred to acquire or create internal use software, principally related to our enterprise resource planning (“ERP”) systems. Our ERP systems are stated at cost, net of accumulated amortization and are amortized using the straight-line method over 10 years. All other internal use computer software are stated at cost, net of accumulated amortization and are amortized using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 7 years.

Significant Accounting Policies Goodwill and Other Intangible Assets (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets We account for our business combinations using the acquisition accounting method, which requires us to determine the fair value of net assets acquired and the related goodwill and other intangible assets. Determining the fair value of assets acquired and liabilities assumed requires management's judgment and involves the use of significant estimates, including projections of future cash inflows and outflows, discount rates, asset lives and market multiples. Considering the characteristics of advertising, specialized marketing and communication services companies, our acquisitions usually do not have significant amounts of tangible assets, as the principal asset we typically acquire is creative talent. As a result, a substantial portion of the purchase price is allocated to goodwill and other intangible assets. We review goodwill and other intangible assets with indefinite lives not subject to amortization as of October 1^st each year and whenever events or significant changes in circumstances indicate that the carrying value may not be recoverable. We evaluate the recoverability of goodwill at a reporting unit level. We have 12 reporting units that were subject to the 2015 annual impairment testing. Our annual impairment review as of October 1, 2015 did not result in an impairment charge for any of our reporting units. For reporting units not included in the qualitative assessment, or for any reporting units identified in the qualitative assessment as "more likely than not" that the fair value is less than its carrying value, the first step of the quantitative impairment test is performed. For our annual impairment test, we compare the respective fair value of our reporting units' equity to the carrying value of their net assets. The first step is a comparison of the fair value of each reporting unit to its carrying value, including goodwill. The sum of the fair values of all our reporting units is reconciled to our current market capitalization plus an estimated control premium. Goodwill allocated to a reporting unit whose fair value is equal to or greater than its carrying value is not impaired, and no further testing is required. Should the carrying amount for a reporting unit exceed its fair value, then the first step of the quantitative impairment test is failed and the magnitude of any goodwill impairment is determined under the second step, which is a comparison of the implied fair value of a reporting unit's goodwill to its carrying value. The implied fair value of goodwill is the excess of the fair value of the reporting unit over its carrying value, excluding goodwill. Impaired goodwill is written down to its implied fair value with a charge to expense in the period the impairment is identified. The fair value of a reporting unit for 2015 and 2014 was estimated using a combination of the income approach, which incorporates the use of the discounted cash flow method, and the market approach, which incorporates the use of earnings and revenue multiples based on market data. We review intangible assets with definite lives subject to amortization whenever events or circumstances indicate that a carrying amount of an asset may not be recoverable. Recoverability of these assets is determined by comparing the carrying value of these assets to the estimated undiscounted future cash flows expected to be generated by these assets. These assets are impaired when their carrying value exceeds their fair value. Impaired intangible assets with definite lives subject to amortization are written down to their fair value with a charge to expense in the period the impairment is identified. Intangible assets with definite lives are amortized on a straight-line basis with estimated useful lives generally between 7 and 15 years. Events or circumstances that might require impairment testing include the loss of a significant client, the identification of other impaired assets within a reporting unit, loss of key personnel, the disposition of a significant portion of a reporting unit, significant decline in stock price or a significant adverse change in business climate or regulations.

Significant Accounting Policies Foreign Currencies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Foreign Currencies	Foreign Currencies The functional currency of our foreign operations is generally their respective local currency. Assets and liabilities are translated at the exchange rates in effect at the balance sheet date, and revenues and expenses are translated at the average exchange rates during the period presented. The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss in the stockholders’ equity section of our Consolidated Balance Sheets. Currency transaction gains or losses primarily arising from transactions in currencies other than the functional currency are included in office and general expenses. Foreign currency transactions resulted in a pre-tax gain of $2.0 in 2015 and pre-tax losses of $1.4 and $0.6 in 2014 and 2013, respectively. We monitor the currencies of countries in which we operate in order to determine if the country should be considered a highly inflationary environment. A currency is determined to be highly inflationary when there is cumulative inflation of approximately 100% or more over a three-year period. If this occurs the functional currency of that country would be changed to our reporting currency, the U.S. Dollar, and foreign exchange gains or losses would be recognized on all monetary transactions, assets and liabilities in currencies other than the U.S. Dollar until the currency is no longer considered highly inflationary.

Significant Accounting Policies Income Taxes (Policies)	12 Months Ended
Significant Accounting Policies Income Taxes (Policies)	Dec. 31, 2015
Accounting Policies [Abstract]
Income Taxes	Income Taxes The provision for income taxes includes U.S. federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be reversed. We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is “more likely than not” that all or a portion of the deferred tax assets will not be realized. We evaluate our tax positions using the “more likely than not” recognition threshold and then apply a measurement assessment to those positions that meet the recognition threshold. The factors used in assessing valuation allowances include all available evidence, such as past operating results, estimates of future taxable income and the feasibility of tax planning strategies. We have established tax reserves that we believe to be adequate in relation to the potential for additional assessments in each of the jurisdictions in which we are subject to taxation. We regularly assess the likelihood of additional tax assessments in those jurisdictions and adjust our reserves as additional information or events require.

- Definition

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

+ References + Details

Significant Accounting Policies Redeemable Noncontrolling Interests (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests Many of our acquisitions include provisions under which the noncontrolling equity owners can require us to purchase additional interests in a subsidiary at their discretion. Payments for these redeemable noncontrolling interests may be contingent on projected operating performance and satisfying other conditions specified in the related agreements. These payments are also subject to revision in accordance with the terms of the agreements. We record these redeemable noncontrolling interests in “mezzanine equity” in our Consolidated Balance Sheets. Each reporting period, redeemable noncontrolling interests are reported at their estimated redemption value, but not less than their initial fair value. Any adjustment to the redemption value above initial value prior to exercise will also impact retained earnings or additional paid-in capital, but will not impact net income. Adjustments as a result of currency translation will affect the redeemable noncontrolling interest balance, but do not impact retained earnings or additional paid-in capital.

Significant Accounting Policies Earnings Per Share (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Earnings Per Share	Earnings Per Share (“EPS”) Basic EPS available to IPG common stockholders equals net income available to IPG common stockholders divided by the weighted-average number of common shares outstanding for the applicable period. Diluted EPS equals net income available to IPG common stockholders adjusted to exclude, if dilutive, preferred stock dividends, interest expense related to potentially dilutive securities calculated using the effective interest rate method and the benefit from the preferred stock repurchased, divided by the weighted-average number of common shares outstanding, plus any additional common shares that would have been outstanding if potentially dilutive shares had been issued. Diluted EPS reflect the potential dilution that would occur if certain potentially dilutive securities or debt obligations were exercised or converted into common stock. The potential issuance of common stock is assumed to occur at the beginning of the year (or at the time of issuance of the potentially dilutive instrument, if later) and the incremental shares are included using the treasury stock or “if-converted” method. The proceeds utilized in applying the treasury stock method consist of the amount, if any, to be paid upon exercise and, as it relates to stock-based compensation, the amount of compensation cost attributed to future service not yet recognized and any tax benefits credited to additional paid-in-capital related to the exercise. These proceeds are then assumed to be used to purchase common stock at the average market price of our stock during the period. The incremental shares (difference between the shares assumed to be issued and the shares assumed to be purchased), to the extent they would have been dilutive, are included in the denominator of the diluted EPS calculation. We may be required to calculate basic EPS using the two-class method as a result of our redeemable noncontrolling interests. To the extent that the redemption value increases and exceeds the then-current fair value of a redeemable noncontrolling interest, net income available to IPG common stockholders (used to calculate EPS) could be negatively impacted by that increase, subject to certain limitations. The partial or full recovery of any reductions to net income available to IPG common stockholders (used to calculate EPS) is limited to any cumulative prior-period reductions. For the years ended December 31, 2015, 2014 and 2013, there was no impact to EPS for adjustments related to our redeemable noncontrolling interests.

Significant Accounting Policies Pension and Postretirement Benefits (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Pension and Postretirement Benefits	Pension and Postretirement Benefits We have pension and postretirement benefit plans covering certain domestic and international employees. We use various actuarial methods and assumptions in determining our net pension and postretirement benefit costs and obligations, including the discount rate used to determine the present value of future benefits, expected long-term rate of return on plan assets and healthcare cost trend rates. The overfunded or underfunded status of our pension and postretirement benefit plans is recorded on our Consolidated Balance Sheet.

- Definition

Disclosure of accounting policy for pension and other postretirement benefit plans. This accounting policy may address (1) the types of plans sponsored by the entity, and the benefits provided by each plan (2) groups that participate in (or are covered by) each plan (3) how plan assets, liabilities and expenses are measured, including the use of any actuaries and (4) significant assumptions used by the entity to value plan assets and liabilities and how such assumptions are derived.

+ References + Details

Significant Accounting Policies Stock-Based Compensation (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Stock-Based Compensation	Stock-Based Compensation Compensation costs related to share-based transactions, including employee stock options, are recognized in the Consolidated Financial Statements based on fair value. Stock-based compensation expense is generally recognized ratably over the requisite service period based on the estimated grant-date fair value, net of estimated forfeitures.

Significant Accounting Policies Treasury Stock (Policies)	12 Months Ended
	Dec. 31, 2015
Treasury Stock [Abstract]
Treasury Stock [Text Block]	Treasury Stock We account for repurchased common stock under the cost method and include such treasury stock as a component of our Consolidated Statements of Stockholders' Equity. Upon retirement, we reduce common stock for the par value of the shares being retired and the excess of the cost of the shares over par value as a reduction to additional paid-in capital ("APIC"), to the extent there is APIC in the same class of stock, and any remaining amount to retained earnings. These retired shares remain authorized but unissued. In October 2015, we retired 11.3 shares of our treasury stock, which resulted in a reduction in common stock of $1.2, treasury stock of $233.2 and APIC of $232.0. There was no effect on total stockholders' equity as a result of the retirement. In November 2014, we retired 121.9 shares of our treasury stock, which resulted in a reduction in common stock of $12.2, treasury stock of $1,522.4 and APIC of $1,510.2. There was no effect on total stockholders' equity as a result of the retirement.

Debt and Credit Agreements Schedule of Long-term Debt Instruments (Tables)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

A summary of the carrying amounts and fair values of our long-term debt is listed below.



	Effective Interest Rate		December 31,
			2015				2014
			Book Value		Fair Value ¹		Book Value		Fair Value ¹
2.25% Senior Notes due 2017 (less unamortized discount and issuance costs of $0.3 and $0.9, respectively)	2.30	%	$	298.8	$	299.3	$	298.3	$	301.2
4.00% Senior Notes due 2022 (less unamortized discount and issuance costs of $2.0 and $1.6, respectively)	4.13	%	246.4		250.9		245.9		255.2
3.75% Senior Notes due 2023 (less unamortized discount and issuance costs of $1.1 and $2.9, respectively)	4.32	%	496.0		484.8		495.5		499.8
4.20% Senior Notes due 2024 (less unamortized discount and issuance costs of $0.8 and $3.4, respectively)	4.24	%	495.8		496.4		495.0		509.8
Other notes payable and capitalized leases			75.2		75.2		80.3		80.3
Total long-term debt			1,612.2				1,615.0
Less: current portion			1.9				2.1
Long-term debt, excluding current portion			$	1,610.3			$	1,612.9


1	See Note 11 for information on the fair value measurement of our long-term debt.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 942
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-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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-Paragraph 2
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

+ Details

Debt and Credit Agreements Schedule of Line of Credit Facility (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Line of Credit Facility [Abstract]

Schedule of Line of Credit Facilities [Table Text Block]

A summary of our credit facilities is presented below.



	December 31,
	2015								2014
	Total Facility		Amount Outstanding		Letters of Credit		Total Available		Total Facility		Amount Outstanding		Letters of Credit		Total Available
Committed credit agreement	$	1,000.0	$	0.0	$	3.7	$	996.3	$	1,000.0	$	0.0	$	16.0	$	984.0
Uncommitted credit agreements	$	744.5	$	150.1	$	1.1	$	593.3	$	740.3	$	107.2	$	3.9	$	629.2

Earnings Per Share Basic and Diluted Earnings Per Common Share Available to IPG Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2015

Earnings Per Share [Abstract]

Basic and Diluted Earnings Per Common Share Available to IPG Common Stockholders

The following sets forth basic and diluted earnings per common share available to IPG common stockholders.



	Years ended December 31,
	2015		2014		2013
Net income available to IPG common stockholders - basic	$	454.6	$	477.1	$	259.2
Adjustments: Effect of dilutive securities
Interest on 4.75% Notes ¹	0.0		0.0		0.8
Net income available to IPG common stockholders - diluted	$	454.6	$	477.1	$	260.0


Weighted-average number of common shares outstanding - basic	408.1		419.2		421.1
Add: Effect of dilutive securities
Restricted stock, stock options and other equity awards	7.6		6.2		5.2
4.75% Notes ¹	0.0		0.0		3.3

Weighted-average number of common shares outstanding - diluted	415.7		425.4		429.6


Earnings per share available to IPG common stockholders - basic	$	1.11	$	1.14	$	0.62
Earnings per share available to IPG common stockholders - diluted	$	1.09	$	1.12	$	0.61


1	We retired all of our outstanding 4.75% Convertible Senior Notes due 2023 (the "4.75% Notes") in March 2013. For purposes of calculating diluted earnings per share for 2013, the potentially dilutive shares are pro-rated based on the period in which they were outstanding.

Earnings Per Share Potential Shares Excluded from Diluted Earnings Per Share Calculation (Tables)

12 Months Ended

Dec. 31, 2015

Potential Shares Excluded from Diluted Earnings Per Share Calculation [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

The following table presents the potential shares excluded from the diluted earnings per share calculation because the effect of including these potential shares would be antidilutive.



	Years ended December 31,
	2015	2014	2013
Preferred Stock Outstanding ¹	0.0	0.0	13.7
Securities excluded from the diluted earnings per share calculation because the exercise price was greater than the average market price:
Stock options ²	0.0	0.0	0.1


1	We converted all of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock into common stock in October 2013. For purposes of calculating diluted earnings per share for 2013, the potentially dilutive shares would have been pro-rated based on the period they were outstanding but were antidilutive.


2	These options were outstanding at the end of the respective periods. In any period in which the exercise price is less than the average market price, these options have the potential to be dilutive, and application of the treasury stock method would reduce this amount.

Acquisitions Cash Paid For Current And Prior Years' Acquisitions (Tables)

12 Months Ended

Dec. 31, 2015

Potential Shares Excluded from Diluted Earnings Per Share Calculation [Abstract]

Cash Paid For Current And Prior Years' Acquisitions [Table Text Block]

Details of cash paid for current and prior years' acquisitions are listed below.



	Years ended December 31,
	2015			2014			2013
Cost of investment: current-year acquisitions	$	37.8		$	97.3		$	67.7
Cost of investment: prior-year acquisitions	53.1			14.0			28.5
Less: net cash acquired	(9.2		)	(29.9		)	(7.1		)
Total cost of investment	81.7			81.4			89.1
Operating expense¹	18.4			3.4			2.0

Total cash paid for acquisitions ²	$	100.1		$	84.8		$	91.1


1	Represents cash payments made that were either in excess of the initial value of contingent payments or contingent upon the future employment of the former owners of the acquired companies and are recorded in the operating section of the Consolidated Statements of Cash Flows.

Supplementary Data Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts (Tables)

12 Months Ended

Dec. 31, 2015

Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts [Abstract]

Schedule of Credit Losses for Financing Receivables, Current [Table Text Block]

Valuation and Qualifying Accounts – Allowance for Uncollectible Accounts Receivable



	Years ended December 31,
	2015			2014			2013
Balance at beginning of period	$	59.5		$	64.9		$	59.0
Charges to costs and expenses	11.4			7.4			12.6
(Reversals) charges to other accounts ¹	(0.4		)	0.1			0.7
Deductions:
Dispositions	(2.4		)	0.0			0.0
Uncollectible accounts written off	(9.8		)	(8.1		)	(7.2		)
Foreign currency translation adjustment	(4.1		)	(4.8		)	(0.2		)
Balance at end of period	$	54.2		$	59.5		$	64.9


1	Amounts primarily represent miscellaneous reclassifications and allowances of acquired companies.

Supplementary Data Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

Property and Equipment



	December 31,
	2015			2014
Furniture and equipment	$	585.1		$	640.7
Leasehold improvements	570.1			594.0
Internal use computer software	295.2			296.2
Land and buildings	78.7			87.3
	1,529.1			1,618.2
Less: accumulated depreciation	(961.9		)	(1,070.0		)
Total property and equipment, net	$	567.2		$	548.2

Intangible Assets Changes in Carrying Value of Goodwill (Tables)

12 Months Ended

Dec. 31, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in Carrying Value of Goodwill

The changes in the carrying value of goodwill for our segments, IAN and CMG, for the years ended December 31, 2015 and 2014 are listed below.



	IAN			CMG			Total ¹
Balance as of December 31, 2013	$	3,097.0		$	532.0		$	3,629.0
Current-year acquisitions	95.2			40.9			136.1
Foreign currency and other	(83.7		)	(12.2		)	(95.9		)
Balance as of December 31, 2014	$	3,108.5		$	560.7		$	3,669.2
Current-year acquisitions	37.8			13.2			51.0
Foreign currency and other	(94.9		)	(16.8		)	(111.7		)
Balance as of December 31, 2015	$	3,051.4		$	557.1		$	3,608.5


1	For all periods presented, we have not recorded a goodwill impairment charge.

Intangible Assets Summary of Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Other Intangible Assets [Abstract]

Schedule of Finite-Lived Intangible Assets [Table Text Block]

The following table provides a summary of other intangible assets, which are included in other assets on our Consolidated Balance Sheets.



	December 31,
	2015							2014
	Gross Amount		Accumulated Amortization			Net Amount		Gross Amount		Accumulated Amortization			Net Amount
Customer lists	$	249.0	$	(150.0	)	$	99.0	$	255.8	$	(139.3	)	$	116.5
Trade names	65.0		(25.7		)	39.3		71.0		(22.8		)	48.2
Other	13.7		(3.7		)	10.0		14.1		(3.8		)	10.3
Total	$	327.7	$	(179.4	)	$	148.3	$	340.9	$	(165.9	)	$	175.0

Income Taxes Schedule of Components of Provision for Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Other Intangible Assets [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

The provision for income taxes is listed below.



	Years ended December 31,
	2015			2014			2013
U.S. federal income taxes (including foreign withholding taxes):
Current	$	117.8		$	8.0		$	46.9
Deferred	46.9			130.7			25.2
	164.7			138.7			72.1
State and local income taxes:
Current	15.1			9.7			(14.7		)
Deferred	13.0			23.8			24.7
	28.1			33.5			10.0
Foreign income taxes:
Current	100.4			115.3			79.6
Deferred	(10.4		)	(71.0		)	19.5
	90.0			44.3			99.1
Total	$	282.8		$	216.5		$	181.2

Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Other Intangible Assets [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

A reconciliation of the effective income tax rate as reflected in our Consolidated Statements of Operations to the U.S. federal statutory income tax rate is listed below.



	Years ended December 31,
	2015			2014			2013
U.S. federal statutory income tax rate	35.0		%	35.0		%	35.0		%

Income tax provision at U.S. federal statutory rate	$	266.8		$	252.3		$	163.8
State and local income taxes, net of federal income tax benefit	18.3			21.4			6.5
Impact of foreign operations, including withholding taxes	16.1			1.7			30.5
Change in net valuation allowance ¹	(20.6		)	(66.0		)	3.2
Worthless securities deduction	0.0			0.0			(22.2		)
Divestitures	11.9			0.0			0.0
Other	(9.7		)	7.1			(0.6		)
Provision for income taxes	$	282.8		$	216.5		$	181.2

Effective income tax rate on operations	37.1		%	30.0		%	38.7		%


1	Reflects changes in valuation allowance that impacted the effective income tax rate for each year presented.

Income Taxes Schedule of Deferred Tax Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Other Intangible Assets [Abstract]

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

The components of deferred tax assets and liabilities are listed below.



	December 31,
	2015			2014
Postretirement/post-employment benefits	$	25.3		$	27.4
Deferred compensation	193.4			191.2
Pension costs	25.8			41.4
Basis differences in fixed assets	(67.5		)	(38.5		)
Rent	41.1			45.8
Interest	60.9			60.9
Accruals and reserves	29.4			34.8
Allowance for doubtful accounts	10.8			10.8
Basis differences in intangible assets	(408.2		)	(412.3		)
Investments in equity securities	(8.3		)	(2.6		)
Tax loss/tax credit carry forwards	354.5			404.4
Restructuring and other reorganization-related costs	0.4			(0.3		)
Prepaid expenses	(2.3		)	0.0
Other	59.9			59.2
Total deferred tax assets, net	315.2			422.2
Valuation allowance	(275.1		)	(332.2		)
Net deferred tax assets	$	40.1		$	90.0

Income Taxes Summary of Valuation Allowance (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Other Intangible Assets [Abstract]

Summary of Valuation Allowance [Table Text Block]

The change in the valuation allowance is listed below.



	Years ended December 31,
	2015			2014			2013
Balance at beginning of period	$	332.2		$	467.3		$	392.9
(Reversed) charged to costs and expenses	(20.8		)	(72.8		)	65.2
(Reversed) charged to gross tax assets and other accounts	(36.3		)	(62.3		)	9.2
Balance at end of period	$	275.1		$	332.2		$	467.3

Restructuring and Other Reorganization-Related Charges (Reversals), net Restructuring Charges (Reversals) by Type (Tables)

12 Months Ended

Dec. 31, 2015

Restructuring and Related Activities [Abstract]

Restructuring Charges (Reversals) by Type

Restructuring and Other Reorganization-Related (Reversals) Charges, net

The components of restructuring and other reorganization-related (reversals) charges, net for all of our restructuring plans are listed below.



	Years ended December 31,
	2015			2014		2013
Severance and termination costs	$	0.0		$	0.1	$	55.9
Lease termination costs	(0.7		)	0.1		4.2
Other exit costs	(0.1		)	0.0		0.5
Total restructuring and other reorganization-related (reversals) charges, net	$	(0.8	)	$	0.2	$	60.6

Restructuring and Other Reorganization-Related Charges (Reversals), net Restructuring Liability Activity for 2013 Plan (Tables)

12 Months Ended

Dec. 31, 2015

Restructuring Liability Activity for 2013 Plan [Abstract]

Schedule of Restructuring Reserve by Type of Cost [Table Text Block]

A summary of the 2013 Plan restructuring liability activity is listed below.



	December 31, 2014		Net Restructuring Reversals			Cash Payments			Foreign Currency Translation Adjustment			December 31, 2015
Severance and termination costs	$	4.4	$	0.0		$	(2.1	)	$	(0.2	)	$	2.1
Lease termination costs	2.6		(0.1		)	(1.0		)	(0.1		)	1.4
Total	$	7.0	$	(0.1	)	$	(3.1	)	$	(0.3	)	$	3.5

Accumulated Other Comprehensive Loss, net of tax Schedule of Accumulated Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2015

Accumulated Other Comprehensive Loss [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

The following table presents the changes in accumulated other comprehensive loss, net of tax by component.



	Foreign Currency Translation Adjustments			Available-for-Sale Securities			Derivative Instruments			Defined Benefit Pension and Other Postretirement Plans			Total
Balance as of December 31, 2013	$	(243.7	)	$	0.4		$	(11.7	)	$	(156.2	)	$	(411.2	)
Other comprehensive (loss) income before reclassifications	(191.7		)	0.7			(0.6		)	(55.0		)	(246.6		)
Amount reclassified from accumulated other comprehensive loss, net of tax	(0.9		)	(0.3		)	1.4			20.9			21.1
Balance as of December 31, 2014	$	(436.3	)	$	0.8		$	(10.9	)	$	(190.3	)	$	(636.7	)
Other comprehensive (loss) income before reclassifications	(252.6		)	0.5			0.0			14.6			(237.5		)
Amount reclassified from accumulated other comprehensive loss, net of tax	23.3			0.0			1.3			4.0			28.6
Balance as of December 31, 2015	$	(665.6	)	$	1.3		$	(9.6	)	$	(171.7	)	$	(845.6	)

Accumulated Other Comprehensive Loss, net of tax Reclassification out of Accumulated Other Comprehensive Income (Tables)

12 Months Ended

Dec. 31, 2015

Restructuring Liability Activity for 2013 Plan [Abstract]

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

Amounts reclassified from accumulated other comprehensive loss, net of tax for the years ended December 31, 2015, 2014 and 2013 are as follows:



	Years ended December 31,									Affected Line Item in the Consolidated Statements of Operations
	2015			2014			2013
Foreign currency translation adjustments	$	23.3		$	(0.9	)	$	0.0		Other (expense) income, net
Gains on available-for-sale securities	0.0			0.0			(1.4		)	Other (expense) income, net
Losses on derivative instruments	2.0			1.9			1.7			Interest expense
Amortization of defined benefit pension and postretirement plans items ¹	10.4			10.5			10.8
Tax effect	(7.1		)	9.6			(2.4		)	Provision for income taxes
Total amount reclassified from accumulated other comprehensive loss, net of tax	$	28.6		$	21.1		$	8.7


1	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 12 for further information.

Incentive Compensation Plans Schedule of Stock-based Compensation Expense (Tables)

12 Months Ended

Dec. 31, 2015

Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]

Schedule of Stock-based Compensation Expense

The amounts of stock-based compensation expense as reflected in salaries and related expenses in our Consolidated Statements of Operations, and the related tax benefit, are listed below.



	Years ended December 31,
	2015		2014		2013
Stock options	$	1.0	$	2.1	$	3.7
Stock-settled awards	11.6		10.0		9.8
Cash-settled awards	0.7		0.6		1.5
Performance-based awards	57.7		42.2		29.6
Employee stock purchase plan	0.7		0.6		0.6
Other ¹	0.9		1.2		0.8
Stock-based compensation expense	$	72.6	$	56.7	$	46.0
Tax benefit	$	26.3	$	20.6	$	17.6


1	Represents charges recorded for severance expense related to stock-based compensation awards.

Incentive Compensation Plans Schedule of Stock Options Activity (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Stock Options Assumptions [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

The following tables are a summary of stock option activity during 2015.



	Options		Weighted- Average Exercise Price (per option)		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Stock options outstanding as of January 1, 2015	7.4		$	9.70
Exercised	(1.4	)	9.99
Stock options outstanding as of December 31, 2015	6.0		$	9.63	3.5	$	82.4
Stock options vested and expected to vest as of December 31, 2015	6.0		$	9.63	3.5	$	82.4
Stock options exercisable as of December 31, 2015	5.8		$	9.51	3.4	$	80.1

	Options		Weighted- Average Grant Date Fair Value (per option)		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Non-vested as of January 1, 2015	0.6		$	4.16
Vested	(0.4	)	4.18
Non-vested as of December 31, 2015	0.2		$	4.14	7.2	$	2.4

Incentive Compensation Plans Summary of Stock Options Assumptions (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Stock Options Assumptions [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair value of each option grant has been estimated with the following weighted-average assumptions.



	Year ended December 31, 2013
Expected volatility ¹	40.2	%
Expected term (years) ²	6.9
Risk-free interest rate ³	1.3	%
Expected dividend yield ⁴	2.4	%


1	The expected volatility used to estimate the fair value of stock options awarded is based on a blend of: (i) historical volatility of our common stock for periods equal to the expected term of our stock options and (ii) implied volatility of tradable forward put and call options to purchase and sell shares of our common stock.


3	The risk-free interest rate is determined using the implied yield currently available for zero-coupon U.S. government issuers with a remaining term equal to the expected term of the options.


4	The expected dividend yield was calculated based on an annualized dividend of $0.30 per share in 2013.

Incentive Compensation Plans Stock-based Compensation, Grants in Period Weighted Average (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Stock Options Assumptions [Abstract]

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block]

Stock-based compensation awards expected to be settled in cash have been classified as liabilities in our Consolidated Balance Sheets as of December 31, 2015 and 2014.



	Years ended December 31,
	2015		2014		2013
Stock-Settled Awards:
Awards granted	0.8		1.2		1.1
Weighted-average grant-date fair value (per award)	$	22.07	$	17.77	$	13.51
Total fair value of vested awards distributed	$	18.8	$	12.6	$	35.4
Cash-Settled Awards:
Awards granted	0.1		0.1		0.1
Weighted-average grant-date fair value (per award)	$	20.46	$	18.20	$	16.35
Total fair value of vested awards distributed	$	0.2	$	0.6	$	5.4
Performance-Based Awards:
Awards granted	2.9		3.5		1.5
Weighted-average grant-date fair value (per award)	$	20.88	$	16.56	$	11.97
Total fair value of vested awards distributed	$	18.7	$	15.3	$	0.2

Incentive Compensation Plans Schedule of Nonvested Stock Activity (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Stock Options Assumptions [Abstract]

Schedule of Nonvested Share Activity [Table Text Block]



	Stock-Settled Awards					Cash-Settled Awards					Performance-Based Awards
	Awards			Weighted- Average Grant-Date Fair Value (per award)		Awards			Weighted- Average Grant-Date Fair Value (per award)		Awards			Weighted- Average Grant-Date Fair Value (per award)
Non-vested as of January 1, 2015	2.2			$	15.47	0.1			$	16.99	5.8			$	14.39
Granted	0.8			22.07		0.1			20.46		2.9			20.88
Vested	(0.9		)	14.10		(0.1		)	11.99		(0.8		)	11.09
Forfeited	(0.1		)	17.92		0.0			0.00		(0.8		)	13.36
Non-vested as of December 31, 2015	2.0			$	18.53	0.1			$	18.75	7.1			$	17.50
Total unrecognized compensation expense remaining	$	16.2				$	1.8				$	87.1
Weighted-average years expected to be recognized over	1.3					1.7					1.8

Fair Value Measurements Fair Value of Assets and Liabilities Measured on a Recurring Basis (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]



	December 31, 2015												Balance Sheet Classification
	Level 1			Level 2			Level 3			Total			Balance Sheet Classification
Assets
Cash equivalents	$	875.7		$	0.0		$	0.0		$	875.7		Cash and cash equivalents
Short-term marketable securities	6.8			0.0			0.0			6.8			Marketable securities
Long-term investments	0.4			0.0			0.0			0.4			Other assets
Total	$	882.9		$	0.0		$	0.0		$	882.9

As a percentage of total assets	7.0		%	0.0		%	0.0		%	7.0		%

Liabilities
Mandatorily redeemable noncontrolling interests ¹	$	0.0		$	0.0		$	45.0		$	45.0

	December 31, 2014												Balance Sheet Classification
	Level 1			Level 2			Level 3			Total			Balance Sheet Classification
Assets
Cash equivalents	$	901.4		$	0.0		$	0.0		$	901.4		Cash and cash equivalents
Short-term marketable securities	6.6			0.0			0.0			6.6			Marketable securities
Long-term investments	0.5			0.0			0.0			0.5			Other assets
Total	$	908.5		$	0.0		$	0.0		$	908.5

As a percentage of total assets	7.1		%	0.0		%	0.0		%	7.1		%

Liabilities
Mandatorily redeemable noncontrolling interests ¹	$	0.0		$	0.0		$	32.8		$	32.8

Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Nonrecurring (Tables)

12 Months Ended

Dec. 31, 2015

Assets and Liabilities Measured at Fair Value on Recurring Basis [Abstract]

Fair Value Measurements, Nonrecurring [Table Text Block]



	December 31, 2015
	Level 1		Level 2		Level 3		Total
Total long-term debt	$	0.0	$	1,531.4	$	75.2	$	1,606.6

Schedule of Defined Benefit Plans Disclosures (Tables)

12 Months Ended

Dec. 31, 2015

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures



	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
December 31,	2015			2014			2015			2014			2015			2014
Benefit Obligation
Projected benefit obligation as of January 1	$	146.9		$	133.1		$	589.5		$	569.9		$	39.5		$	37.9
Service cost	0.0			0.0			11.1			10.3			0.0			0.1
Interest cost	0.3			6.2			18.9			23.4			1.5			1.7
Benefits paid	(9.3		)	(10.4		)	(20.9		)	(24.1		)	(5.9		)	(5.6		)
Plan participant contributions	0.0			0.0			0.5			0.6			1.5			1.5
Actuarial (gains) losses	(11.0		)	18.0			(28.0		)	55.7			(2.3		)	4.4
Settlements and curtailments	0.0			0.0			(2.4		)	(4.0		)	0.0			0.0
Foreign currency effect	0.0			0.0			(30.1		)	(42.8		)	0.0			0.0
Other	0.0			0.0			(0.7		)	0.5			(0.4		)	(0.5		)

Projected benefit obligation as of December 31	$	126.9		$	146.9		$	537.9		$	589.5		$	33.9		$	39.5

Fair Value of Plan Assets
Fair value of plan assets as of January 1	$	111.5		$	109.6		$	415.5		$	398.5		$	0.0		$	0.0
Actual return on plan assets	(4.3		)	9.6			4.0			44.7			0.0			0.0
Employer contributions	3.2			2.7			21.6			25.7			4.4			4.1
Plan participant contributions	0.0			0.0			0.5			0.6			1.5			1.5
Benefits paid	(9.3		)	(10.4		)	(20.9		)	(24.1		)	(5.9		)	(5.6		)
Settlements	0.0			0.0			(2.0		)	(4.0		)	0.0			0.0
Foreign currency effect	0.0			0.0			(19.1		)	(25.9		)	0.0			0.0
																0.0
Fair value of plan assets as of December 31	$	101.1		$	111.5		$	399.6		$	415.5		$	0.0		$	0.0

Funded status of the plans at December 31	$	(25.8	)	$	(35.4	)	$	(138.3	)	$	(174.0	)	$	(33.9	)	$	(39.5	)



	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
December 31,	2015			2014			2015			2014			2015			2014
Amounts recognized in Consolidated Balance Sheets
Non-current asset	$	0.0		$	0.0		$	8.8		$	8.3		$	0.0		$	0.0
Current liability	0.0			0.0			(6.4		)	(8.0		)	(3.5		)	(4.0		)
Non-current liability	(25.8		)	(35.4		)	(140.7		)	(174.3		)	(30.4		)	(35.5		)

Net liability recognized	$	(25.8	)	$	(35.4	)	$	(138.3	)	$	(174.0	)	$	(33.9	)	$	(39.5	)

Accumulated benefit obligation	$	126.9		$	146.9		$	518.6		$	566.2

Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	$	49.9		$	56.1		$	137.3		$	161.0		$	0.6		$	2.9
Prior service cost (credit)	0.0			0.0			0.6			1.1			(0.7		)	(0.4		)

Total amount recognized	$	49.9		$	56.1		$	137.9		$	162.1		$	(0.1	)	$	2.5



	Domestic Pension Plan				Foreign Pension Plans
December 31,	2015		2014		2015		2014
Pension plans with underfunded or unfunded accumulated benefit obligation
Aggregate projected benefit obligation	$	126.9	$	146.9	$	525.9	$	577.1
Aggregate accumulated benefit obligation	126.9		146.9		511.1		559.5
Aggregate fair value of plan assets	101.1		111.5		379.2		395.8

Employee Benefits Schedule of Net Benefit Costs (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Net Benefit Costs [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

The components of net periodic benefit cost and key assumptions are listed below.



	Domestic Pension Plan									Foreign Pension Plans									Domestic Postretirement Benefit Plan
Years ended December 31,	2015			2014			2013			2015			2014			2013			2015			2014			2013
Service cost	$	0.0		$	0.0		$	0.0		$	11.1		$	10.3		$	9.9		$	0.0		$	0.1		$	0.1
Interest cost	0.3			6.2			5.5			18.9			23.4			21.7			1.5			1.7			1.6
Expected return on plan assets	(7.6		)	(7.3		)	(7.7		)	(20.6		)	(24.7		)	(19.2		)	0.0			0.0			0.0
Settlement and curtailment (gains) losses	0.0			0.0			0.0			(0.2		)	0.5			(0.1		)	0.0			0.0			0.0
Amortization of:
Prior service cost (credit)	0.0			0.0			0.0			0.1			0.2			0.2			(0.1		)	(0.2		)	(0.1		)
Net actuarial losses	6.5			6.6			7.9			4.1			3.4			2.8			0.0			0.0			0.0
Net periodic cost	$	(0.8	)	$	5.5		$	5.7		$	13.4		$	13.1		$	15.3		$	1.4		$	1.6		$	1.6

Assumptions



	Domestic Pension Plan						Foreign Pension Plans						Domestic Postretirement Benefit Plan
Years ended December 31,	2015		2014		2013		2015		2014		2013		2015		2014		2013

Net periodic cost
Discount rate	4.15	%	4.85	%	4.00	%	3.41	%	4.29	%	4.32	%	4.00	%	4.85	%	4.00	%
Rate of compensation increase	N/A		N/A		N/A		2.99	%	3.97	%	3.57	%	N/A		N/A		N/A
Expected return on plan assets	7.00	%	7.00	%	7.00	%	5.01	%	6.18	%	5.24	%	N/A		N/A		N/A

Benefit obligation
Discount rate	4.80	%	4.15	%	4.85	%	3.61	%	3.41	%	4.29	%	4.65	%	4.00	%	4.85	%
Rate of compensation increase	N/A		N/A		N/A		3.25	%	2.98	%	3.97	%	N/A		N/A		N/A

Health care cost trend rate assumed for next year
Initial rate (weighted-average)													7.00	%	7.00	%	7.50	%
Year ultimate rate is reached													2024		2019		2019
Ultimate rate													5.00	%	5.00	%	5.00	%

Employee Benefits Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Net Benefit Costs [Abstract]

Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block]

The following table presents additional information about our domestic and foreign pension plan assets for which we utilize Level 3 inputs to determine fair value.



	Year ended December 31, 2015												Year ended December 31, 2014
	Investment Funds			Limited Partnerships			Other			Total			Investment Funds			Limited Partnerships			Other			Total
Balance at beginning of period	$	40.1		$	32.1		$	0.3		$	72.5		$	25.4		$	36.1		$	0.6		$	62.1
Actual return on assets:
Assets sold during the year	0.0			0.0			0.0			0.0			0.2			0.2			0.0			0.4
Assets still held at year end	(0.7		)	(1.1		)	0.0			(1.8		)	(0.7		)	(0.3		)	(0.3		)	(1.3		)
Net purchases, sales and settlements	18.5			0.0			0.1			18.6			15.2			(3.9		)	0.0			11.3
Transfers in/out of Level 3	0.0			0.0			(0.4		)	(0.4		)	0.0			0.0			0.0			0.0
Balance at end of period	$	57.9		$	31.0		$	0.0		$	88.9		$	40.1		$	32.1		$	0.3		$	72.5

Segment Information Schedule of Segment Reporting Information, by Segment (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

Summarized financial information concerning our reportable segments is shown in the following table.



	Years ended December 31,
	2015			2014			2013
Revenue:
IAN	$	6,144.9		$	6,076.3		$	5,772.8
CMG	1,468.9			1,460.8			1,349.5
Total	$	7,613.8		$	7,537.1		$	7,122.3

Segment operating income (loss):
IAN	$	846.6		$	774.7		$	660.0
CMG	166.3			163.4			139.7
Corporate and other	(141.8		)	(149.5		)	(140.8		)
Total	871.1			788.6			658.9

Restructuring and other reorganization-related reversals (charges), net	0.8			(0.2		)	(60.6		)
Interest expense	(85.8		)	(84.9		)	(122.7		)
Interest income	22.8			27.4			24.7
Other expense, net	(46.7		)	(10.2		)	(32.3		)
Income before income taxes	$	762.2		$	720.7		$	468.0

Depreciation and amortization of fixed assets and intangible assets:
IAN	$	117.5		$	124.5		$	125.8
CMG	18.4			18.5			15.8
Corporate and other	21.1			20.0			15.8
Total	$	157.0		$	163.0		$	157.4

Capital expenditures:
IAN	$	117.5		$	92.0		$	108.9
CMG	12.7			11.7			18.6
Corporate and other	30.9			45.0			45.5
Total	$	161.1		$	148.7		$	173.0

	December 31,
	2015			2014
Total assets:
IAN	$	10,738.2		$	11,080.2
CMG	1,338.6			1,347.5
Corporate and other	508.3			308.9
Total	$	12,585.1		$	12,736.6

Segment Information Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Net Benefit Costs [Abstract]

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

Revenue and long-lived assets, excluding intangible assets, are presented by major geographic area in the following table.



	Revenue						Long-Lived Assets
	Years ended December 31,						December 31,
	2015		2014		2013		2015		2014
Domestic	$	4,475.5	$	4,184.0	$	3,972.6	$	600.1	$	572.9
International:
United Kingdom	687.7		688.3		568.3		56.3		56.7
Continental Europe	697.2		804.7		800.6		58.6		66.4
Asia Pacific	916.9		922.5		868.9		108.8		102.2
Latin America	383.5		470.4		464.5		45.0		69.2
Other	453.0		467.2		447.4		38.0		32.4
Total International	3,138.3		3,353.1		3,149.7		306.7		326.9
Total Consolidated	$	7,613.8	$	7,537.1	$	7,122.3	$	906.8	$	899.8

Commitments and Contingencies Schedule of Future Minimum Lease Commitments (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Net Benefit Costs [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]



Period	Rent Obligations		Sublease Rental Income			Net Rent
2016	$	322.0	$	(4.4	)	$	317.6
2017	300.4		(1.9		)	298.5
2018	272.2		(0.8		)	271.4
2019	246.1		(0.7		)	245.4
2020	224.5		0.0			224.5
Thereafter	909.0		0.0			909.0
Total	$	2,274.2	$	(7.8	)	$	2,266.4

Commitments and Contingencies Schedule of Contingent Acquisition Obligations (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Net Benefit Costs [Abstract]

Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block]

The following table details the estimated future contingent acquisition obligations payable in cash as of December 31, 2015.



	2016		2017		2018		2019		2020		Thereafter		Total
Deferred acquisition payments	$	53.8	$	39.2	$	13.1	$	13.6	$	7.5	$	3.1	$	130.3
Redeemable noncontrolling interests and call options with affiliates ¹	48.4		70.5		43.0		6.4		5.2		11.9		185.4
Total contingent acquisition payments	102.2		109.7		56.1		20.0		12.7		15.0		315.7
Less: cash compensation expense included above	0.2		0.2		0.1		0.1		0.1		0.0		0.7
Total	$	102.0	$	109.5	$	56.0	$	19.9	$	12.6	$	15.0	$	315.0

Results by Quarter (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

Results by Quarter (Unaudited)



	Three Months Ended March 31,						Three Months Ended June 30,						Three Months Ended September 30,						Three Months Ended December 31,
	2015			2014			2015			2014			2015			2014			2015			2014
Revenue	$	1,676.0		$	1,637.5		$	1,876.1		$	1,851.4		$	1,865.5		$	1,841.1		$	2,196.2		$	2,207.1
Salaries and related expenses	1,215.2			1,188.6			1,205.2			1,170.2			1,202.2			1,195.2			1,235.1			1,266.4
Office and general expenses	453.1			461.1			455.1			484.7			472.1			474.7			504.7			507.6
Restructuring and other reorganization-related (reversals) charges, net	(0.1		)	(0.5		)	0.0			0.7			(0.7		)	(0.1		)	0.0			0.1
Operating income (loss)	7.8			(11.7		)	215.8			195.8			191.9			171.3			456.4			433.0
Other income (expense), net ¹	0.3			1.7			0.5			(11.2		)	(37.2		)	(0.6		)	(10.3		)	(0.1		)
Total (expenses) and other income¹	(13.4		)	(12.3		)	(14.8		)	(27.2		)	(52.9		)	(13.8		)	(28.6		)	(14.4		)
(Benefit of) provision for income taxes ²	(1.4		)	(1.7		)	77.7			65.3			61.1			65.0			145.4			87.9
Net (loss) income	(4.2		)	(22.4		)	123.8			103.7			78.0			92.8			282.9			331.3
Net (loss) income available to IPG common stockholders ²	$	(1.8	)	$	(20.9	)	$	121.2		$	99.4		$	74.9		$	89.7		$	260.3		$	308.9
(Loss) earnings per share available to IPG common stockholders:
Basic	$	0.00		$	(0.05	)	$	0.30		$	0.24		$	0.18		$	0.21		$	0.65		$	0.75
Diluted	$	0.00		$	(0.05	)	$	0.29		$	0.23		$	0.18		$	0.21		$	0.63		$	0.73

Dividends declared per common stock	$	0.120		$	0.095		$	0.120		$	0.095		$	0.120		$	0.095		$	0.120		$	0.095


1	The three months ended December 31, 2015 included pre-tax losses of $12.0 on sales of businesses. The three months ended September 30, 2015 included pre-tax losses of $38.0 on sales of businesses. The three months ended June 30, 2014 included a pre-tax loss of $10.4 related to our early extinguishment of debt.


2	The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.

^[1]

[1]

The three months ended December 31, 2015 included pre-tax losses of $12.0 on sales of businesses. The three months ended September 30, 2015 included pre-tax losses of $38.0 on sales of businesses. The three months ended June 30, 2014 included a pre-tax loss of $10.4 related to our early extinguishment of debt.

Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
ERP Systems, Useful Life	10
Leasehold Improvements, Useful Life	the shorter of the useful life or the remaining lease term
Number of Reporting Units for Purposes of Annual Goodwill Impairment Test	12
Foreign Currency Transaction pre-tax (Gain) Loss	$ (2.0)	$ 1.4	$ 0.6
Minimum
Property and Equipment, Useful Life	3 years
Buildings, Useful Life	10 years
Other Internal Use Software, Useful Life	3
Finite-Lived Intangible Assets, Useful Life	7 years
Maximum
Property and Equipment, Useful Life	7 years
Buildings, Useful Life	35 years
Other Internal Use Software, Useful Life	7
Finite-Lived Intangible Assets, Useful Life	15 years

Debt and Credit Agreements Long-Term Debt (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Apr. 03, 2014

Debt Instrument [Line Items]

Long-term Debt, Gross

$ 1,612.2

$ 1,615.0

Long-term Debt, Current Maturities

1.9

2.1

Long-term Debt, Excluding Current Maturities

1,610.3

1,612.9

Debt Instrument, Unamortized Debt Issuance Costs

15.0

16.6

2.25% Notes

Debt Instrument [Line Items]

Debt Instrument, Face Amount

300.0

Long-term Debt, Gross

298.8

298.3

Debt Instrument, Unamortized Discount

0.3

Debt Instrument, Unamortized Debt Issuance Costs

0.9

Long-term Debt, Fair Value

^[1]

$ 299.3

301.2

Debt Instrument, Maturity Date

Nov. 15, 2017

Interest Rate, Stated Percentage

2.25%

Debt Instrument, Interest Rate, Effective Percentage

2.30%

4.00% Notes

Debt Instrument [Line Items]

Debt Instrument, Face Amount

$ 250.0

Long-term Debt, Gross

246.4

245.9

Debt Instrument, Unamortized Discount

2.0

Debt Instrument, Unamortized Debt Issuance Costs

1.6

Long-term Debt, Fair Value

^[1]

$ 250.9

255.2

Debt Instrument, Maturity Date

Mar. 15, 2022

Interest Rate, Stated Percentage

4.00%

Debt Instrument, Interest Rate, Effective Percentage

4.13%

3.75% Notes

Debt Instrument [Line Items]

Debt Instrument, Face Amount

$ 500.0

Long-term Debt, Gross

496.0

495.5

Debt Instrument, Unamortized Discount

1.1

Debt Instrument, Unamortized Debt Issuance Costs

2.9

Long-term Debt, Fair Value

^[1]

$ 484.8

499.8

Debt Instrument, Maturity Date

Feb. 15, 2023

Interest Rate, Stated Percentage

3.75%

Debt Instrument, Interest Rate, Effective Percentage

4.32%

4.20% Notes

Debt Instrument [Line Items]

Debt Instrument, Face Amount

$ 500.0

Long-term Debt, Gross

495.8

495.0

Debt Instrument, Unamortized Discount

0.8

$ 0.9

Debt Instrument, Unamortized Debt Issuance Costs

3.4

$ 4.4

Long-term Debt, Fair Value

^[1]

$ 496.4

509.8

Debt Instrument, Maturity Date

Apr. 15, 2024

Interest Rate, Stated Percentage

4.20%

Debt Instrument, Interest Rate, Effective Percentage

4.24%

Notes Payable, Other Payables [Member]

Debt Instrument [Line Items]

Long-term Debt, Gross

$ 75.2

80.3

Long-term Debt, Fair Value

^[1]

$ 75.2

$ 80.3

[1]	See Note 11 for information on the fair value measurement of our long-term debt.

Debt and Credit Agreements Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 03, 2014
Debt Instrument [Line Items]
Debt Instrument, Unamortized Debt Issuance Costs	$ 15.0	$ 16.6
Proceeds from Issuance of Long-term Debt	0.1	499.1	$ 0.0
Cash debt pooling arrangements, amount netted	1,608.3	1,590.7
4.20% Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 500.0
Interest Rate, Stated Percentage	4.20%
Long-term Debt, Gross				$ 499.1
Debt Instrument, Unamortized Discount	$ 0.8			0.9
Debt Instrument, Unamortized Debt Issuance Costs	$ 3.4			$ 4.4
Proceeds from Issuance of Long-term Debt		494.7
Repurchase Price Percentage Due to Change of Control	101.00%
6.25% Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 350.0
Interest Rate, Stated Percentage		6.25%

Debt and Credit Agreements Extinguishment of Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Extinguishment of Debt [Line Items]
Gains (Losses) on Extinguishment of Debt	$ 0.0	$ (10.4)	$ (45.2)
6.25% Notes
Extinguishment of Debt [Line Items]
Debt Instrument, Face Amount		$ 350.0
Interest Rate, Stated Percentage		6.25%
Debt Instrument, Maturity Date		Nov. 15, 2014
Early Repayment of Senior Debt		$ 371.2
Accrued Interest, Paid		10.3
Gains (Losses) on Extinguishment of Debt		$ 10.4

Debt and Credit Agreements Annual Maturities (Details) $ in Millions	Dec. 31, 2015 USD ($)
Debt Disclosure [Abstract]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 1.9
Long-term Debt, Maturities, Repayments of Principal in Year Two	323.3
Long-term Debt, Maturities, Repayments of Principal in Year Three	1.8
Long-term Debt, Maturities, Repayments of Principal in Year Four	1.8
Long-term Debt, Maturities, Repayments of Principal in Year Five	0.9
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 1,282.5

Debt and Credit Agreements Credit Facility (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Line of Credit Facility [Line Items]

Line of Credit Facility Commitment Increase

$ 250.0

Line of Credit Facility Limits on Letters of Credit

$ 200.0

Margin for base rate advances

0.30%

Margin for Eurocurrency rate advances

1.30%

Annual rate for fronting fees accrued on letters of credit

0.25%

Annual facility fee

0.20%

Leverage ratio maximum

^[1]

3.50x

Interest coverage ratio minimum

^[2]

5.00x

Committed credit facility [Member]

Line of Credit Facility [Line Items]

Line of Credit Facility, Maximum Borrowing Capacity

$ 1,000.0

Line of Credit Facility, Amount Outstanding

0.0

Letters of Credit Outstanding, Amount

3.7

16.0

Line of Credit Facility, Remaining Borrowing Capacity

996.3

984.0

Uncommitted credit facility

Line of Credit Facility [Line Items]

Line of Credit Facility, Maximum Borrowing Capacity

744.5

740.3

Line of Credit Facility, Amount Outstanding

150.1

107.2

Letters of Credit Outstanding, Amount

1.1

3.9

Line of Credit Facility, Remaining Borrowing Capacity

$ 593.3

$ 629.2

Line of Credit Facility Weighted Average Interest Rate

3.00%

5.00%

[1]

[2]

The interest coverage ratio is defined as EBITDA, as defined in the Credit Agreement, to net interest expense.

Earnings Per Share Basic and Diluted (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Net income available to IPG common stockholders - basic

$ 260.3

$ 74.9

$ 121.2

$ (1.8)

$ 308.9

^[1]

$ 89.7

$ 99.4

$ (20.9)

$ 454.6

$ 477.1

$ 259.2

Interest on convertible debt

^[2]

0.0

0.8

Net income available to IPG common stockholders - diluted

$ 454.6

$ 477.1

$ 260.0

Weighted-average number of common shares outstanding - basic

408.1

419.2

421.1

Restricted stock, stock options and other equity awards

7.6

6.2

5.2

Convertible debt securities

^[2]

0.0

3.3

Weighted-average number of common shares outstanding - diluted

415.7

425.4

429.6

Earnings per share available to IPG common stockholders - basic

$ 0.65

$ 0.18

$ 0.30

$ 0.00

$ 0.75

$ 0.21

$ 0.24

$ (0.05)

$ 1.11

$ 1.14

$ 0.62

Earnings per share available to IPG common stockholders - diluted

$ 0.63

$ 0.18

$ 0.29

$ 0.00

$ 0.73

$ 0.21

$ 0.23

$ (0.05)

$ 1.09

$ 1.12

$ 0.61

[1]	The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.
[2]	We retired all of our outstanding 4.75% Convertible Senior Notes due 2023 (the "4.75% Notes") in March 2013. For purposes of calculating diluted earnings per share for 2013, the potentially dilutive shares are pro-rated based on the period in which they were outstanding.

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References + Details

Antidilutive Shares (Details) - shares
shares in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Preferred Stock Outstanding

Antidilutive Securities

Securities Excluded from Computation of Earnings Per Share, Amount

^[1]

0.0

13.7

Stock options

Antidilutive Securities

Stock options 2

^[2]

0.0

0.1

[1]	1We converted all of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock into common stock in October 2013. For purposes of calculating diluted earnings per share for 2013, the potentially dilutive shares would have been pro-rated based on the period they were outstanding but were antidilutive.
[2]	These options were outstanding at the end of the respective periods. In any period in which the exercise price is less than the average market price, these options have the potential to be dilutive, and application of the treasury stock method would reduce this amount.

Acquisitions Narrative (Details) $ in Millions	12 Months Ended
Acquisitions Narrative (Details) $ in Millions	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 61.0	$ 185.0	$ 97.0
Number of Businesses Acquired	5	8	11
IAN
Number of Businesses Acquired	4	6	9
CMG
Number of Businesses Acquired	1	2	2

Redeemable Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Redeemable Noncontrolling Interests
Balance at beginning of period	$ 257.4	$ 249.1	$ 227.2
Change in related noncontrolling interest balance	0.8	3.2	4.6
Changes in redemption value of redeemable noncontrolling interests:
Additions	16.5	18.7	16.2
Redemptions and reclassifications	(25.1)	(7.9)	(2.3)
Redemption Value Adjustments	2.3	(5.7)	3.4
Balance at end of period	$ 251.9	$ 257.4	$ 249.1

Acquisitions Cash Paid for Acquisitions (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Cash Paid for Acquisitions [Abstract]

Cost of investment: current-year acquisitions

$ 37.8

$ 97.3

$ 67.7

Cost of investment: prior-year acquisitions

53.1

14.0

28.5

Cash Acquired from Acquisition

(9.2)

(29.9)

(7.1)

Total cost of investment

81.7

81.4

89.1

Operating expense

^[1]

18.4

3.4

2.0

Total cash paid for acquisitions

^[2]

100.1

84.8

91.1

Payments for Previous Acquisitions, Financing Cash Flows

53.1

13.6

27.6

Payments for Initial Acquisitions, Investing Cash Flows

$ 28.6

$ 67.8

$ 61.5

[1]

Represents cash payments made that were either in excess of the initial value of contingent payments or contingent upon the future employment of the former owners of the acquired companies

[2]

Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts Receivable (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Movement in Valuation Allowances and Reserves [Roll Forward]

Balance at beginning of period

$ 59.5

$ 64.9

$ 59.0

Charges to costs and expenses

11.4

7.4

12.6

Reversals to other accounts

^[1]

(0.4)

0.1

0.7

Deductions:

Dispositions

(2.4)

0.0

Uncollectible accounts written off

(9.8)

(8.1)

(7.2)

Foreign currency translation adjustment

(4.1)

(4.8)

(0.2)

Balance at end of period

$ 54.2

$ 59.5

$ 64.9

[1]	Amounts primarily represent miscellaneous reclassifications and allowances of acquired companies.

Supplementary Data Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Depreciation, Depletion and Amortization	$ 130.9	$ 133.7	$ 133.2
Furniture and equipment	585.1	640.7
Leasehold improvements	570.1	594.0
Internal use computer software	295.2	296.2
Land and buildings	78.7	87.3
Property and Equipment	1,529.1	1,618.2
Less: accumulated depreciation	961.9	1,070.0
Total property and equipment, net	$ 567.2	$ 548.2

Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities [Abstract]
Salaries, benefits and related expenses	$ 502.4	$ 510.6
Office and related expenses	51.0	51.5
Acquisition obligations	50.1	88.1
Interest	17.3	18.3
Restructuring and other reorganization-related	3.3	5.5
Other	136.2	122.0
Total accrued liabilities	$ 760.3	$ 796.0

Other (Expense) Income, Net (Details) - USD ($)
$ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2015

^[1]

Sep. 30, 2015

^[1]

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

^[1]

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

(Losses) gains on sales of businesses and investments

$ (49.6)

$ 0.8

$ 1.5

Loss on early extinguishment of debt

0.0

10.4

45.2

Vendor discounts and credit adjustments

0.8

3.3

8.6

Other income (expense), net

2.1

(3.9)

2.8

Total other expense, net

$ (10.3)

$ (37.2)

$ 0.5

$ 0.3

$ (0.1)

$ (0.6)

$ (11.2)

$ 1.7

$ (46.7)

$ (10.2)

$ (32.3)

[1]

Share Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of shares repurchased	13.6	14.9	31.8
Aggregated cost, including fees	$ 285.2	$ 275.1	$ 481.8
Average price per share, including fees	$ 20.97	$ 18.41	$ 15.17
2016 Share Repurchase Program
Share repurchase program, initial authorized amount	$ 300.0
2015 Share Repurchase Program
Remaining available for repurchase	158.6
2014 Share Repurchase Program
Share repurchase program, initial authorized amount	$ 300.0
2013 Share Repurchase Program
Share repurchase program, initial authorized amount		$ 300.0
Share repurchase program, increased authorized amount		$ 500.0

Supplemental Cash Flow Information (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Supplemental Cash Flow Information [Abstract]

Cash paid for interest

$ 74.5

$ 78.1

$ 110.7

Cash paid for income taxes, net of refunds

^[1]

231.9

103.9

111.8

Proceeds from Income Tax Refunds

$ 13.0

$ 21.3

$ 15.0

[1]	Refunds of $13.0, $21.3 and $15.0 were received for the years ended December 31, 2015, 2014 and 2013, respectively.

Goodwill (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Goodwill

Goodwill

$ 3,608.5

$ 3,669.2

$ 3,629.0

^[1]

Current year acquisitions

51.0

136.1

Foreign currency and other

(111.7)

(95.9)

IAN

Goodwill

Goodwill

^[1]

3,051.4

3,108.5

3,097.0

Current year acquisitions

37.8

95.2

Foreign currency and other

(94.9)

(83.7)

CMG

Goodwill

Goodwill

^[1]

557.1

560.7

$ 532.0

Current year acquisitions

13.2

40.9

Foreign currency and other

$ (16.8)

$ (12.2)

[1]	For all periods presented, we have not recorded a goodwill impairment charge.

Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Future Amortization Expense 2016	$ 23.2
Future Amortization Expense 2017	21.7
Future Amortization Expense 2018	20.1
Future Amortization Expense 2019	17.1
Future Amortization Expense 2020	16.0
Finite-Lived Intangible Assets [Line Items]
Amortization Expense of Intangible Assets	26.1	$ 29.4	$ 26.8
Acquired Finite-Lived Intangible Assets related to Acquisitions	9.6	48.6
Gross Amount	327.7	340.9
Accumulated Amortization	(179.4)	(165.9)
Net Amount	148.3	175.0
Customer Lists
Finite-Lived Intangible Assets [Line Items]
Gross Amount	249.0	255.8
Accumulated Amortization	(150.0)	(139.3)
Net Amount	99.0	116.5
Trade Names
Finite-Lived Intangible Assets [Line Items]
Gross Amount	65.0	71.0
Accumulated Amortization	(25.7)	(22.8)
Net Amount	39.3	48.2
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Amount	13.7	14.1
Accumulated Amortization	(3.7)	(3.8)
Net Amount	$ 10.0	$ 10.3
Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Useful Life	7 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Useful Life	15 years

Components of Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income before income taxes, Domestic	$ 461.0	$ 387.7	$ 255.3
Income before income taxes, Foreign	301.2	333.0	212.7
Income before income taxes	$ 762.2	$ 720.7	$ 468.0

Provision for Income Taxes (Details) - USD ($)
$ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

^[1]

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

U.S. federal income taxes (including foreign withholding taxes):

Current federal income taxes

$ 117.8

$ 8.0

$ 46.9

Deferred federal income taxes

46.9

130.7

25.2

Total federal income taxes

164.7

138.7

72.1

State and local income taxes:

Current state and local income taxes

15.1

9.7

(14.7)

Deferred state and local income taxes

13.0

23.8

24.7

Total state and local income taxes

28.1

33.5

10.0

Foreign income taxes:

Current foreign income taxes

100.4

115.3

79.6

Deferred foreign income taxes

(10.4)

(71.0)

19.5

Total foreign income taxes

90.0

44.3

99.1

Total provision for income taxes

$ 145.4

$ 61.1

$ 77.7

$ (1.4)

$ 87.9

$ 65.0

$ 65.3

$ (1.7)

$ 282.8

$ 216.5

$ 181.2

[1]	The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.

Reconciliation of Effective Income Tax Rate (Details) - USD ($)
$ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

^[2]

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Valuation Allowance [Line Items]

U.S. federal statutory income tax rate

35.00%

Income tax provision at U.S. federal statutory rate

$ 266.8

$ 252.3

$ 163.8

State and local income taxes, net of federal income tax benefit

18.3

21.4

6.5

Impact of foreign operations, including withholding taxes

16.1

1.7

30.5

Change in Net Valuation Allowance

^[1]

(20.6)

(66.0)

3.2

Worthless securities deduction

0.0

(22.2)

Divestitures

11.9

0.0

Other

(9.7)

7.1

(0.6)

Total provision for income taxes

$ 145.4

$ 61.1

$ 77.7

$ (1.4)

$ 87.9

$ 65.0

$ 65.3

$ (1.7)

$ 282.8

$ 216.5

$ 181.2

Effective income tax rate on operations

37.10%

30.00%

38.70%

[1]	Reflects changes in valuation allowance that impacted the effective income tax rate for each year presented.
[2]	The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.

Components of Deferred Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Tax Assets, Net [Abstract]
Postretirement/post-employment benefits	$ 25.3	$ 27.4
Deferred compensation	193.4	191.2
Pension costs	25.8	41.4
Basis differences in fixed assets	(67.5)	(38.5)
Rent	41.1	45.8
Interest	60.9	60.9
Accruals and reserves	29.4	34.8
Allowance for doubtful accounts	10.8	10.8
Basis differences in intangible assets	(408.2)	(412.3)
Investments in equity securities	(8.3)	(2.6)
Tax loss/tax credit carry forwards	354.5	404.4
Restructuring and other reorganization-related costs	0.4	(0.3)
Prepaid expenses	(2.3)	0.0
Other	59.9	59.2
Total Deferred Tax Assets, Net	315.2	422.2
Valuation allowance	(275.1)	(332.2)	$ (467.3)	$ (392.9)
Net Deferred Tax Assets	$ 40.1	$ 90.0

Income Taxes Change in Valuation Allowances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Valuation Allowances
Deferred Tax Assets, Valuation Allowance	$ 275.1	$ 332.2	$ 467.3	$ 392.9
(Reversed) charged to costs and expenses	(20.8)	(72.8)	65.2
(Reversed) charged to gross tax assets and other accounts	(36.3)	(62.3)	$ 9.2
Operating Loss Carryforwards	1,127.7
Deferred Tax Liabilities, Undistributed Foreign Earnings	2,592.4	$ 2,214.2
Foreign Tax Authority
Summary of Valuation Allowances
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration	984.2
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	143.5
State and Local Jurisdiction [Member]
Summary of Valuation Allowances
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 56.7
Minimum \| Foreign Tax Authority
Summary of Valuation Allowances
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2016
Maximum \| Foreign Tax Authority
Summary of Valuation Allowances
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2035
Maximum \| State and Local Jurisdiction [Member]
Summary of Valuation Allowances
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2035

Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract]
Balance at beginning of period	$ 238.0	$ 219.2	$ 194.6
Increases as a result of tax positions taken during a prior year	5.2	29.0	8.3
Decreases as a result of tax positions taken during a prior year	(19.7)	(16.3)	(1.9)
Settlements with taxing authorities	(4.1)	(1.1)	(34.9)
Lapse of statutes of limitation	(3.8)	(4.1)	(10.6)
Increases as a result of tax positions taken during the current year	11.3	11.3	63.7
Balance at end of period	226.9	238.0	$ 219.2
Income Tax Contingency [Line Items]
Unrecognized tax benefits that would impact effective tax rate	206.5
Income tax penalties and interest accrued	20.1	15.3
Income tax penalties and interest expense	(4.8)	$ (5.4)
Minimum [Member]
Income Tax Contingency [Line Items]
Anticipated decrease in unrecognized tax benefits	25.0
Maximum [Member]
Income Tax Contingency [Line Items]
Anticipated decrease in unrecognized tax benefits	$ 35.0

Restructuring and Other Reorganization-Related Charges (Reversals), net (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring and other reorganization-related (reversals) charges, net	$ 0.0	$ (0.7)	$ 0.0	$ (0.1)	$ 0.1	$ (0.1)	$ 0.7	$ (0.5)	$ (0.8)	$ 0.2	$ 60.6
Severance and termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other reorganization-related (reversals) charges, net									0.0	0.1	55.9
Payments for Restructuring									2.1
Restructuring Reserve, Translation Adjustment									(0.2)
Restructuring Reserve	2.1				4.4				2.1	4.4
Lease termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other reorganization-related (reversals) charges, net									(0.7)	0.1	4.2
Payments for Restructuring									1.0
Restructuring Reserve, Translation Adjustment									(0.1)
Restructuring Reserve	1.4				2.6				1.4	2.6
Other exit costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other reorganization-related (reversals) charges, net									(0.1)	0.0	$ 0.5
2013 Restructuring Plan [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring and other reorganization-related (reversals) charges, net									(0.1)
Payments for Restructuring									3.1
Restructuring Reserve, Translation Adjustment									(0.3)
Restructuring Reserve	$ 3.5				$ 7.0				3.5	$ 7.0
2013 Restructuring Plan [Domain] \| Lease termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other reorganization-related (reversals) charges, net									$ (0.1)

Accumulated Other Comprehensive Loss, net of tax Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes in fair value of available-for-sale securities	$ 0.5	$ 0.7	$ 0.8
Changes in fair value of derivative instruments	0.0	(0.6)	0.0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(237.5)	(246.6)
Total Reclassification from AOCI	28.6	21.1	8.7
Accumulated Other Comprehensive Income (Loss), Net of Tax	(845.6)	(636.7)	(411.2)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	(252.6)	(191.7)
Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	23.3	(0.9)
Foreign Currency Translation Adjustment, Net of Tax	(665.6)	(436.3)	(243.7)
Available-for-sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes in fair value of available-for-sale securities	0.5	0.7
Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	0.0	(0.3)
Available-for-sale Securities Adjustment, Net of Tax	1.3	0.8	0.4
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes in fair value of derivative instruments	0.0	(0.6)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	1.3	1.4
Cumulative Changes in Net Gain (Loss) from Hedges, Effect Net of Tax	(9.6)	(10.9)	(11.7)
Defined Benefit and Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments and Tax	14.6	(55.0)
Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	4.0	20.9
Pension and Other Postretirement Benefit Plans, Net of Tax	$ 171.7	$ (190.3)	$ (156.2)

Accumulated Other Comprehensive Loss, net of tax Reclassifications from AOCI, net of tax (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]

Income tax effect

$ (7.1)

$ 9.6

$ (2.4)

Total Reclassification from AOCI

28.6

21.1

8.7

Foreign Currency Translation Adjustment

Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]

Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax

23.3

(0.9)

0.0

Available-for-sale Securities

Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]

Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax

0.0

1.4

Derivative Instruments

Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]

Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax

2.0

1.9

1.7

Defined Benefit and Postretirement Plans

Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]

Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax

^[1]

$ 10.4

$ 10.5

$ 10.8

[1]	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 12 for further information

Plan Information (Details) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) shares
Incentive Compensation Plan Initiation Year	2014
Number of shares initially available for grant	28.8
Maximum shares participants are eligible to receive	2.0
Cash Award performance vesting condition	range from 0% to 300% of the target amount
Maximum Cash Award Per Employee \| $	$ 10.0
Number of years stock options expire from grant date	10 years
Fair Value of shares on grant date is amortized over vesting period, years	3 years
Minimum [Member]
Stock options exercisable period	2 years
Maximum [Member]
Stock options exercisable period	4 years

Incentive Compensation Plans Employee Stock Purchase Plans (Details)	12 Months Ended
	Dec. 31, 2015 shares
Prior Employee stock purchase plan
Stock Issued During Period, Shares, Employee Stock Purchase Plans	3,000,000
2016 Employee stock purchase plan
Maximum Employee Subscription Rate	10.00%
Maximum Number of Shares Per Employee	900
Employee Stock Purchase Plan description	90% of the lesser of the average market price of a share on the first business day of the offering period or the average market price of a share on the last business day of the offering period of three months
Employee Stock Ownership Plan (ESOP), Shares Contributed to ESOP	10,000,000

Stock Based Compensation Expense (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Stock-based Payment Award

Stock-based compensation expense

$ 72.6

$ 56.7

$ 46.0

Tax benefit

26.3

20.6

17.6

Employee Stock Option

Stock-based Payment Award

Stock-based compensation expense

1.0

2.1

3.7

Stock-settled awards

Stock-based Payment Award

Stock-based compensation expense

11.6

10.0

9.8

Cash-settled awards

Stock-based Payment Award

Stock-based compensation expense

0.7

0.6

1.5

Performance-based awards

Stock-based Payment Award

Stock-based compensation expense

57.7

42.2

29.6

Employee stock purchase plan

Stock-based Payment Award

Stock-based compensation expense

0.7

0.6

Other

Stock-based Payment Award

Stock-based compensation expense

^[1]

$ 0.9

$ 1.2

$ 0.8

[1]	Represents charges recorded for severance expense related to stock-based compensation awards.

Incentive Compensation Plans Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-based Payment Award
Intrinsic value of stock options exercised	$ 16.1	$ 10.7	$ 26.2
Proceeds from Stock Options Exercised including Taxes Withheld	$ 20.4	$ 25.2	$ 59.5
Weighted average grant date fair value per option			$ 4.14
Employee Stock Option
Stock-based Payment Award
Stock options outstanding as of January 1, 2014	7.4
Stock options outstanding as of Jan 1, 2014, Weighted-average exercise price	$ 9.70
Exercised	(1.4)	(1.7)	(5.2)
Exercised, Weighted-average exercise price	$ 9.99
Stock options outstanding as of December 31, 2014	6.0	7.4
Stock options outstanding as of Dec 31, 2014, Weighted-average exercise price	$ 9.63	$ 9.70
Options outstanding, Weighted Average Remaining Contractual Term	3 years 6 months
Stock options outstanding, Aggregate intrinsic value	$ 82.4
Stock options vested and expected to vest, Outstanding	6.0
Stock options vested and expected to vest, Weighted-average exercise price	$ 9.63
Options Vested and Expected. Weighted Average Remaining Contractual Term	3 years 6 months
Stock options vested and expected to vest, Aggregate intrinsic value	$ 82.4
Stock options exercisable, Number	5.8
Stock options exercisable, Weighted-average exercise price	$ 9.51
Options exercisable, Weighted-average remaining contractual term	3 years 5 months
Stock options exercisable, Aggregate intrinsic value	$ 80.1
Employee Stock Option Non vested [Member]
Stock-based Payment Award
Stock options outstanding as of January 1, 2014	0.6
Stock options outstanding as of Jan 1, 2014, Weighted-average exercise price	$ 4.16
Stock options outstanding as of December 31, 2014	0.2	0.6
Stock options outstanding as of Dec 31, 2014, Weighted-average exercise price	$ 4.14	$ 4.16
Options outstanding, Weighted Average Remaining Contractual Term	7 years 2 months
Stock options outstanding, Aggregate intrinsic value	$ 2.4
Vested	(0.4)
Vested, Weighted-average grant date fair value	$ 4.18
Performance based cash awards settled in shares
Stock-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 16.6	$ 19.8
Total unrecognized compensation expense remaining	$ 1.6
Weighted-average years expected to be recognized over	2 months

Stock Option Valuation Assumptions (Details)

12 Months Ended

Dec. 31, 2013

$ / shares

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]

Expected volatility

40.20%

^[1]

Expected term (years)

6 years 11 months

^[2]

Risk free interest rate

1.30%

^[3]

Expected dividend yield

2.40%

^[4]

Annualized dividend per share used in calculation of expected dividend yield

$ 0.30

[1]	The expected volatility used to estimate the fair value of stock options awarded is based on a blend of: (i) historical volatility of our common stock for periods equal to the expected term of our stock options and (ii) implied volatility of tradable forward put and call options to purchase and sell shares of our common stock.
[2]	The estimate of our expected term is based on the average of: (i) an assumption that all outstanding options are exercised upon achieving their full vesting date and (ii) an assumption that all outstanding options will be exercised at the midpoint between the current date (i.e., the date awards have ratably vested through) and their full contractual term. In determining the estimate, we considered several factors, including the historical option exercise behavior of our employees and the terms and vesting periods of the options.
[3]	The risk-free interest rate is determined using the implied yield currently available for zero-coupon U.S. government issuers with a remaining term equal to the expected term of the options.
[4]	The expected dividend yield was calculated based on an annualized dividend of $0.30 per share in 2013.

Share-based Compensation Awards (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-settled awards
Stock-based Payment Award
Stock based awards expected to be settled in cash	0.8	1.2	1.1
Weighted-average grant-date fair value (per award)	$ 22.07	$ 17.77	$ 13.51
Total fair value of vested awards distributed	$ 18.8	$ 12.6	$ 35.4
Accrued dividends on non-vested stock-settled awards	0.9	0.8
Dividends paid for stock-settled awards	$ 0.6	$ 0.5
Cash-settled awards
Stock-based Payment Award
Stock based awards expected to be settled in cash	0.1	0.1	0.1
Weighted-average grant-date fair value (per award)	$ 20.46	$ 18.20	$ 16.35
Total fair value of vested awards distributed	$ 0.2	$ 0.6	$ 5.4
Performance-based awards
Stock-based Payment Award
Stock based awards expected to be settled in cash	2.9	3.5	1.5
Weighted-average grant-date fair value (per award)	$ 20.88	$ 16.56	$ 11.97
Total fair value of vested awards distributed	$ 18.7	$ 15.3	$ 0.2
Performance based cash awards settled in shares
Stock-based Payment Award
Total fair value of vested awards distributed	$ 16.6	$ 19.8

Non-vested Award Activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-settled awards
Stock-based Payment Award
Non-vested as of January 1, 2014	2.2
Nonvested as of January 1, 2014, Weighted-average grant date fair value	$ 15.47
Granted	0.8
Granted, Weighted-average grant-date fair value	$ 22.07	$ 17.77	$ 13.51
Vested	(0.9)
Vested, Weighted-average grant date fair value	$ 14.10
Forfeited	(0.1)
Forfeited, Weighted-average grant date fair value	$ 17.92
Non-vested as of December 31, 2014	2.0	2.2
Nonvested as of December 31, 2014, Weighted-average grant date fair value	$ 18.53	$ 15.47
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 18.8	$ 12.6	$ 35.4
Total unrecognized compensation expense remaining	$ 16.2
Weighted-average years expected to be recognized over	1 year 3 months
Cash-settled awards
Stock-based Payment Award
Non-vested as of January 1, 2014	0.1
Nonvested as of January 1, 2014, Weighted-average grant date fair value	$ 16.99
Granted	0.1
Granted, Weighted-average grant-date fair value	$ 20.46	$ 18.20	$ 16.35
Vested	(0.1)
Vested, Weighted-average grant date fair value	$ 11.99
Forfeited	0.0
Forfeited, Weighted-average grant date fair value	$ 0.00
Non-vested as of December 31, 2014	0.1	0.1
Nonvested as of December 31, 2014, Weighted-average grant date fair value	$ 18.75	$ 16.99
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 0.2	$ 0.6	$ 5.4
Total unrecognized compensation expense remaining	$ 1.8
Weighted-average years expected to be recognized over	1 year 8 months
Performance-based awards
Stock-based Payment Award
Non-vested as of January 1, 2014	5.8
Nonvested as of January 1, 2014, Weighted-average grant date fair value	$ 14.39
Granted	2.9
Granted, Weighted-average grant-date fair value	$ 20.88	$ 16.56	$ 11.97
Vested	(0.8)
Vested, Weighted-average grant date fair value	$ 11.09
Forfeited	(0.8)
Forfeited, Weighted-average grant date fair value	$ 13.36
Non-vested as of December 31, 2014	7.1	5.8
Nonvested as of December 31, 2014, Weighted-average grant date fair value	$ 17.50	$ 14.39
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 18.7	$ 15.3	$ 0.2
Total unrecognized compensation expense remaining	$ 87.1
Weighted-average years expected to be recognized over	1 year 9 months
Performance based cash awards settled in shares
Stock-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 16.6	19.8
Cash awards granted during the period target value	1.2	2.9	35.6
Total unrecognized compensation expense remaining	$ 1.6
Weighted-average years expected to be recognized over	2 months
Cash Awards Total Target Value
Stock-based Payment Award
Cash awards granted during the period target value	$ 1.3	5.8	4.6
Recognized in salaries and related expense	3.0	3.1	4.0
Performance based cash awards
Stock-based Payment Award
Cash awards granted during the period target value	31.8	33.0	47.4
Recognized in salaries and related expense	$ 35.8	$ 27.3	$ 18.3

Fair Value on a Recurring Basis (Details) - USD ($)
$ in Millions

Dec. 31, 2015

Dec. 31, 2014

Level 1

Fair value assets and liabilities measured on recurring basis

Cash equivalents

$ 875.7

$ 901.4

Short-term marketable securities

6.8

6.6

Long-term investments

0.4

0.5

Fair value of total assets, recurring

$ 882.9

$ 908.5

Fair value of assets measured on a recurring basis, percentage of total assets

7.00%

7.10%

Mandatorily redeemable noncontrolling interests

^[1]

$ 0.0

Level 2

Fair value assets and liabilities measured on recurring basis

Cash equivalents

0.0

Short-term marketable securities

0.0

Long-term investments

0.0

Fair value of total assets, recurring

$ 0.0

Fair value of assets measured on a recurring basis, percentage of total assets

0.00%

Mandatorily redeemable noncontrolling interests

^[1]

$ 0.0

Level 3

Fair value assets and liabilities measured on recurring basis

Restructuring Reserve

3.9

8.1

Cash equivalents

0.0

Short-term marketable securities

0.0

Long-term investments

0.0

Fair value of total assets, recurring

$ 0.0

Fair value of assets measured on a recurring basis, percentage of total assets

0.00%

Mandatorily redeemable noncontrolling interests

$ 45.0

$ 32.8

^[1]

Fair Value, Total

Fair value assets and liabilities measured on recurring basis

Cash equivalents

875.7

901.4

Short-term marketable securities

6.8

6.6

Long-term investments

0.4

0.5

Fair value of total assets, recurring

$ 882.9

$ 908.5

Fair value of assets measured on a recurring basis, percentage of total assets

7.00%

7.10%

Mandatorily redeemable noncontrolling interests

^[1]

$ 45.0

$ 32.8

[1]

Fair Value Unobservable Inputs (Details) - Mandatorily redeemable noncontrolling interests - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair value assets and liabilities measured on recurring basis unobservable input reconciliation
Balance at beginning of period, mandatorily redeemable noncontrolling interests	$ 32.8	$ 27.0
Level 3 additions	23.7	5.6
Level 3 reductions	(17.2)	(0.8)
Realized losses included in net income	5.3	1.0
Foreign currency translation	0.4	0.0
Balance at end of period, mandatorily redeemable noncontrolling interests	$ 45.0	$ 32.8

Fair Value on a Nonrecurring Basis (Details) $ in Millions	Dec. 31, 2015 USD ($)
Level 1
Fair value assets and liabilities measured on nonrecurring basis
Fair Value	$ 0.0
Level 2
Fair value assets and liabilities measured on nonrecurring basis
Fair Value	1,531.4
Level 3
Fair value assets and liabilities measured on nonrecurring basis
Fair Value	75.2
Fair Value, Total
Fair value assets and liabilities measured on nonrecurring basis
Fair Value	$ 1,606.6

Employee Benefits (Details) $ in Millions	12 Months Ended
Employee Benefits (Details) $ in Millions	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Number of Participants Domestic Pension Plan	3,700
Number of Participants Postretirement Benefit Plan	1,900
Deferred Compensation Arrangements [Abstract]
Deferred Compensation Liability	$ 95.7	$ 97.7
Deferred Compensation Expense	6.3	9.8	$ 13.4
Deferred Benefit Liability	141.5	153.2
Deferred Benefit Expense	9.7	10.8	$ 14.0
Cash Surrender Value of Life Insurance	167.0	165.6
Deferred Compensation Plan Assets	10.7	$ 8.5
Supplemental Unemployment Benefits [Abstract]
Health and Life Insurance Benefit Obligation	8.0
Income Replacement Benefit Obligation	$ 0.0

Pension and Postretirement Benefit Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	$ 527.0
Fair Value of Plan Assets (Period End)	500.7	$ 527.0
Domestic Pension Plan
Benefit Obligation [Roll Forward]
Benefit Obligation (Period Start)	146.9	133.1
Service cost	0.0	0.0	$ 0.0
Interest cost	0.3	6.2	5.5
Benefits paid	(9.3)	(10.4)
Plan participant contributions	0.0	0.0
Actuarial losses (gains)	(11.0)	18.0
Settlements and curtailments	0.0	0.0
Foreign currency effect	0.0	0.0
Other	0.0	0.0
Benefit Obligation (Period End)	126.9	146.9	133.1
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	111.5	109.6
Actual return on plan assets	(4.3)	9.6
Employer contributions	3.2	2.7
Plan participant contributions	0.0	0.0
Benefits paid	(9.3)	(10.4)
Settlements	0.0	0.0
Foreign currency effect	0.0	0.0
Fair Value of Plan Assets (Period End)	101.1	111.5	109.6
Defined Benefit Plan, Funded Status of Plan	(25.8)	(35.4)
Amounts Recognized in Consolidated Balance Sheets
Non-current asset	0.0	0.0
Current liability	0.0	0.0
Non-current liability	(25.8)	(35.4)
Net liability recognized	(25.8)	(35.4)
Accumulated benefit obligation	126.9	146.9
Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	49.9	56.1
Prior service cost (credit)	0.0	0.0
Total amount recognized	49.9	56.1
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Loss in Next Fiscal Year	7.5
Pension plans with underfunded or unfunded accumulated benefit obligation
Aggregate projected benefit obligation	126.9	146.9
Aggregate accumulated benefit obligation	126.9	146.9
Aggregate fair value of plan assets	101.1	111.5
Foreign Pension Plans
Benefit Obligation [Roll Forward]
Benefit Obligation (Period Start)	589.5	569.9
Service cost	11.1	10.3	9.9
Interest cost	18.9	23.4	21.7
Benefits paid	(20.9)	(24.1)
Plan participant contributions	0.5	0.6
Actuarial losses (gains)	(28.0)	55.7
Settlements and curtailments	(2.4)	(4.0)
Foreign currency effect	(30.1)	(42.8)
Other	(0.7)	0.5
Benefit Obligation (Period End)	537.9	589.5	569.9
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	415.5	398.5
Actual return on plan assets	4.0	44.7
Employer contributions	21.6	25.7
Plan participant contributions	0.5	0.6
Benefits paid	(20.9)	(24.1)
Settlements	(2.0)	(4.0)
Foreign currency effect	(19.1)	(25.9)
Fair Value of Plan Assets (Period End)	399.6	415.5	398.5
Defined Benefit Plan, Funded Status of Plan	(138.3)	(174.0)
Amounts Recognized in Consolidated Balance Sheets
Non-current asset	8.8	8.3
Current liability	(6.4)	(8.0)
Non-current liability	(140.7)	(174.3)
Net liability recognized	(138.3)	(174.0)
Accumulated benefit obligation	518.6	566.2
Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	137.3	161.0
Prior service cost (credit)	0.6	1.1
Total amount recognized	137.9	162.1
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Loss in Next Fiscal Year	3.7
Pension plans with underfunded or unfunded accumulated benefit obligation
Aggregate projected benefit obligation	525.9	577.1
Aggregate accumulated benefit obligation	511.1	559.5
Aggregate fair value of plan assets	379.2	395.8
Domestic Postretirement Benefit Plan
Benefit Obligation [Roll Forward]
Benefit Obligation (Period Start)	39.5	37.9
Service cost	0.0	0.1	0.1
Interest cost	1.5	1.7	1.6
Benefits paid	(5.9)	(5.6)
Plan participant contributions	1.5	1.5
Actuarial losses (gains)	(2.3)	4.4
Settlements and curtailments	0.0	0.0
Foreign currency effect	0.0	0.0
Other	(0.4)	(0.5)
Benefit Obligation (Period End)	33.9	39.5	37.9
Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets (Period Start)	0.0	0.0
Actual return on plan assets	0.0	0.0
Employer contributions	4.4	4.1
Plan participant contributions	1.5	1.5
Benefits paid	(5.9)	(5.6)
Settlements	0.0	0.0
Foreign currency effect	0.0	0.0
Fair Value of Plan Assets (Period End)	0.0	0.0	$ 0.0
Defined Benefit Plan, Funded Status of Plan	(33.9)	(39.5)
Amounts Recognized in Consolidated Balance Sheets
Non-current asset	0.0	0.0
Current liability	(3.5)	(4.0)
Non-current liability	(30.4)	(35.5)
Net liability recognized	(33.9)	(39.5)
Amounts recognized in Accumulated Other Comprehensive Loss, net
Net actuarial loss	0.6	2.9
Prior service cost (credit)	(0.7)	(0.4)
Total amount recognized	$ (0.1)	$ 2.5

Net Periodic Cost (Details) - USD ($) $ in Millions	12 Months Ended
Net Periodic Cost (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Domestic Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 0.0	$ 0.0	$ 0.0
Interest cost	0.3	6.2	5.5
Expected return on plan assets	(7.6)	(7.3)	(7.7)
Settlement and curtailment (gains) losses	0.0	0.0	0.0
Amortization of:
Prior service cost (credit)	0.0	0.0	0.0
Unrecognized actuarial losses	6.5	6.6	7.9
Defined Benefit Plan, Net Periodic Benefit Cost	$ (0.8)	$ 5.5	$ 5.7
Net Periodic Benefit, Discount Rate	4.15%	4.85%	4.00%
Expected Long-term Return on Assets	7.00%	7.00%	7.00%
Benefit Obligation, Discount Rate	4.80%	4.15%	4.85%
Foreign Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 11.1	$ 10.3	$ 9.9
Interest cost	18.9	23.4	21.7
Expected return on plan assets	(20.6)	(24.7)	(19.2)
Settlement and curtailment (gains) losses	(0.2)	0.5	(0.1)
Amortization of:
Prior service cost (credit)	0.1	0.2	0.2
Unrecognized actuarial losses	4.1	3.4	2.8
Defined Benefit Plan, Net Periodic Benefit Cost	$ 13.4	$ 13.1	$ 15.3
Net Periodic Benefit, Discount Rate	3.41%	4.29%	4.32%
Net Periodic Benefit, Rate of Compensation Increase	2.99%	3.97%	3.57%
Expected Long-term Return on Assets	5.01%	6.18%	5.24%
Benefit Obligation, Discount Rate	3.61%	3.41%	4.29%
Benefit Obligation, Rate of Compensation Increase	3.25%	2.98%	3.97%
Domestic Postretirement Benefit Plan
Defined Benefit Plan, Net Periodic Benefit Cost
Service cost	$ 0.0	$ 0.1	$ 0.1
Interest cost	1.5	1.7	1.6
Expected return on plan assets	0.0	0.0	0.0
Settlement and curtailment (gains) losses	0.0	0.0	0.0
Amortization of:
Prior service cost (credit)	(0.1)	(0.2)	(0.1)
Unrecognized actuarial losses	0.0	0.0	0.0
Defined Benefit Plan, Net Periodic Benefit Cost	$ 1.4	$ 1.6	$ 1.6
Net Periodic Benefit, Discount Rate	4.00%	4.85%	4.00%
Benefit Obligation, Discount Rate	4.65%	4.00%	4.85%
Health Care Cost Trend Rate Assumed for Next Year	7.00%	7.00%	7.50%
Year Ultimate Trend Rate is Reached	2024	2019	2019
Ultimate Health Care Cost Trend Rate	5.00%	5.00%	5.00%

Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	$ 500.7	$ 527.0
Balance at beginning of period	72.5	62.1
Actual return on plan assets:
Assets sold during the year	0.0	0.4
Assets still held at year end	(1.8)	(1.3)
Net purchases, sales and settlements	18.6	11.3
Defined Benefit Plan, Transfers Between Measurement Levels	(0.4)	0.0
Balance at end of period	88.9	72.5
Level 1
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	61.9	61.2
Level 2
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	349.9	393.3
Level 3
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	88.9	72.5
Investment funds
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	410.5	431.5
Balance at beginning of period	40.1	25.4
Actual return on plan assets:
Assets sold during the year	0.0	0.2
Assets still held at year end	(0.7)	(0.7)
Net purchases, sales and settlements	18.5	15.2
Defined Benefit Plan, Transfers Between Measurement Levels	0.0	0.0
Balance at end of period	57.9	40.1
Investment funds \| Level 1
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	16.8	18.8
Investment funds \| Level 2
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	335.8	372.6
Investment funds \| Level 3
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	57.9	40.1
Insurance contracts
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	13.7	19.3
Insurance contracts \| Level 1
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.0	0.0
Insurance contracts \| Level 2
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	13.7	19.3
Insurance contracts \| Level 3
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.0	0.0
Limited partnerships
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	31.0	32.1
Balance at beginning of period	32.1	36.1
Actual return on plan assets:
Assets sold during the year	0.0	0.2
Assets still held at year end	(1.1)	(0.3)
Net purchases, sales and settlements	0.0	(3.9)
Defined Benefit Plan, Transfers Between Measurement Levels	0.0	0.0
Balance at end of period	31.0	32.1
Limited partnerships \| Level 1
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.0	0.0
Limited partnerships \| Level 2
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.0	0.0
Limited partnerships \| Level 3
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	31.0	32.1
Fixed Income Funds
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	22.5	19.0
Fixed Income Funds \| Level 1
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	22.1	17.6
Fixed Income Funds \| Level 2
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.4	1.4
Fixed Income Funds \| Level 3
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.0	0.0
Other plan assets
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	23.0	25.1
Balance at beginning of period	0.3	0.6
Actual return on plan assets:
Assets sold during the year	0.0	0.0
Assets still held at year end	0.0	(0.3)
Net purchases, sales and settlements	0.1	0.0
Defined Benefit Plan, Transfers Between Measurement Levels	(0.4)	0.0
Balance at end of period	0.0	0.3
Other plan assets \| Level 1
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	23.0	24.8
Other plan assets \| Level 2
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	0.0	0.0
Other plan assets \| Level 3
Fair value assets and liabilities measured on recurring basis
Fair Value of Plan Assets	$ 0.0	$ 0.3

Employee Benefits Allocation of Plan Assets (Details)	12 Months Ended
Employee Benefits Allocation of Plan Assets (Details)	Dec. 31, 2015	Dec. 31, 2014
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	100.00%
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%	100.00%
Equity securities
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	23.00%
Defined Benefit Plan, Actual Plan Asset Allocations	22.00%	22.00%
Fixed income securities
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	41.00%
Defined Benefit Plan, Actual Plan Asset Allocations	38.00%	46.00%
Real estate
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	8.00%
Defined Benefit Plan, Actual Plan Asset Allocations	7.00%	5.00%
Other plan assets
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	28.00%
Defined Benefit Plan, Actual Plan Asset Allocations	33.00%	27.00%

Pension Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
Pension Cash Flows (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Domestic Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions	$ 3.2	$ 2.7
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	0.0
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
Expected Future Benefit Payments in 2016	13.1
Expected Future Benefit Payments in 2017	12.9
Expected Future Benefit Payments in 2018	8.6
Expected Future Benefit Payments in 2019	8.4
Expected Future Benefit Payments in 2020	8.2
Expected Future Benefit Payments in 2021-2025	38.7
Foreign Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions	21.6	25.7
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	21.0
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
Expected Future Benefit Payments in 2016	21.1
Expected Future Benefit Payments in 2017	23.1
Expected Future Benefit Payments in 2018	24.0
Expected Future Benefit Payments in 2019	24.6
Expected Future Benefit Payments in 2020	22.2
Expected Future Benefit Payments in 2021-2025	126.5
Domestic Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer contributions	4.4	$ 4.1
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
Expected Future Benefit Payments in 2016	3.9
Expected Future Benefit Payments in 2017	3.8
Expected Future Benefit Payments in 2018	3.7
Expected Future Benefit Payments in 2019	3.5
Expected Future Benefit Payments in 2020	3.3
Expected Future Benefit Payments in 2021-2025	13.6
Disclosure of Expected Federal Subsidy Receipts
Prescription Drug Subsidy Receipts in 2016	0.4
Prescription Drug Subsidy Receipts in 2017	0.4
Prescription Drug Subsidy Receipts in 2018	0.4
Prescription Drug Subsidy Receipts in 2019	0.4
Prescription Drug Subsidy Receipts in 2020	0.4
Prescription Drug Subsidy Receipts in 2021-2025	$ 1.9

Savings Plans (Details) - USD ($) $ in Millions	12 Months Ended
Savings Plans (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Domestic Tax Authority
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	$ 44.5	$ 43.0	$ 37.7
Discretionary Company Contribution
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	5.8	5.2	4.9
Defined Contribution Plans Participant Forfeitures
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	(3.8)	3.6	(3.3)
Foreign Tax Authority
Defined Benefit Plans and Other Postretirement Benefit Plans
Cost Recognized	$ 43.9	$ 42.4	$ 36.9

Segment Operations (Details) - USD ($)
$ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Segments:

Revenue

$ 2,196.2

$ 1,865.5

$ 1,876.1

$ 1,676.0

$ 2,207.1

$ 1,841.1

$ 1,851.4

$ 1,637.5

$ 7,613.8

$ 7,537.1

$ 7,122.3

Segment operating income

871.1

788.6

658.9

Restructuring and other reorganization-related reversals (charges), net

0.0

0.7

0.0

0.1

(0.1)

0.1

(0.7)

0.5

0.8

(0.2)

(60.6)

Interest expense

85.8

84.9

122.7

Interest income

22.8

27.4

24.7

Other expense, net

10.3

^[1]

$ 37.2

^[1]

$ (0.5)

$ (0.3)

0.1

$ 0.6

$ 11.2

^[1]

$ (1.7)

46.7

10.2

32.3

Income before income taxes

762.2

720.7

468.0

Depreciation and amortization of fixed assets and intangible assets

157.0

163.0

157.4

Capital expenditures

161.1

148.7

173.0

Assets

12,585.1

12,736.6

12,585.1

12,736.6

IAN

Segments:

Revenue

6,144.9

6,076.3

5,772.8

Segment operating income

846.6

774.7

660.0

Depreciation and amortization of fixed assets and intangible assets

117.5

124.5

125.8

Capital expenditures

117.5

92.0

108.9

Assets

10,738.2

11,080.2

10,738.2

11,080.2

CMG

Segments:

Revenue

1,468.9

1,460.8

1,349.5

Segment operating income

166.3

163.4

139.7

Depreciation and amortization of fixed assets and intangible assets

18.4

18.5

15.8

Capital expenditures

12.7

11.7

18.6

Assets

1,338.6

1,347.5

1,338.6

1,347.5

Corporate and Other

Segments:

Segment operating income

(141.8)

(149.5)

(140.8)

Depreciation and amortization of fixed assets and intangible assets

21.1

20.0

15.8

Capital expenditures

30.9

45.0

$ 45.5

Assets

$ 508.3

$ 308.9

$ 508.3

$ 308.9

[1]

Segment Information Major Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues and Long-Lived Assets
Long-Lived Assets	$ 906.8				$ 899.8				$ 906.8	$ 899.8
Revenue	2,196.2	$ 1,865.5	$ 1,876.1	$ 1,676.0	2,207.1	$ 1,841.1	$ 1,851.4	$ 1,637.5	7,613.8	7,537.1	$ 7,122.3
Domestic
Revenues and Long-Lived Assets
Long-Lived Assets	600.1				572.9				600.1	572.9
Revenue									4,475.5	4,184.0	3,972.6
Total International
Revenues and Long-Lived Assets
Long-Lived Assets	306.7				326.9				306.7	326.9
Revenue									3,138.3	3,353.1	3,149.7
United Kingdom
Revenues and Long-Lived Assets
Long-Lived Assets	56.3				56.7				56.3	56.7
Revenue									687.7	688.3	568.3
Continental Europe
Revenues and Long-Lived Assets
Long-Lived Assets	58.6				66.4				58.6	66.4
Revenue									697.2	804.7	800.6
Asia Pacific
Revenues and Long-Lived Assets
Long-Lived Assets	108.8				102.2				108.8	102.2
Revenue									916.9	922.5	868.9
Latin America
Revenues and Long-Lived Assets
Long-Lived Assets	45.0				69.2				45.0	69.2
Revenue									383.5	470.4	464.5
Other
Revenues and Long-Lived Assets
Long-Lived Assets	$ 38.0				$ 32.4				38.0	32.4
Revenue									$ 453.0	$ 467.2	$ 447.4

Commitments and Contingencies Net Rent Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Gross rent expense	$ 336.5	$ 357.7	$ 366.1
Third-party sublease rental income	(5.5)	(6.1)	(16.1)
Net rent expense	$ 331.0	$ 351.6	$ 350.0

Future Minimum Lease Payments (Details) $ in Millions	Dec. 31, 2015 USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Rent Obligations, due 2016	$ 322.0
Rent Obligations, due 2017	300.4
Rent Obligations, due 2018	272.2
Rent Obligations, due 2019	246.1
Rent Obligations, due 2020	224.5
Rent Obligations, due thereafter	909.0
Total Rent Obligations	2,274.2
Sublease Rental Income, due 2016	(4.4)
Sublease Rental Income, due 2017	(1.9)
Sublease Rental Income, due 2018	(0.8)
Sublease Rental Income, due 2019	(0.7)
Sublease Rental Income, due 2020	0.0
Sublease Rental Income, due thereafter	0.0
Total Sublease Rental Income	(7.8)
Net Rent, due 2016	317.6
Net Rent, due 2017	298.5
Net Rent, due 2018	271.4
Net Rent, due 2019	245.4
Net Rent, due 2020	224.5
Net Rent, due thereafter	909.0
Total Net Rent	$ 2,266.4

Guarantees (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Parent company guarantees on lease obligations	$ 619.4	$ 580.4
Parent company guarantees relating to credit facilities	336.5	$ 329.2
Assets pledged as security for parent company guarantees	$ 0.0

Contingent Acquisition Obligations (Details)
$ in Millions

Dec. 31, 2015

USD ($)

Deferred acquisition payments

Business Acquisition, Contingent Consideration [Line Items]

Future Contingent Acquisition Obligation Due in 2016

$ 53.8

Future Contingent Acquisition Obligation Due in 2017

39.2

Future Contingent Acquisition Obligation Due in 2018

13.1

Future Contingent Acquisition Obligation Due in 2019

13.6

Future Contingent Acquisition Obligation Due in 2020

7.5

Future Contingent Acquisition Obligation Due Thereafter

3.1

Future Contingent Acquisition Obligation Due, Total

130.3

Redeemable noncontrolling interests and call options with affiliates

Business Acquisition, Contingent Consideration [Line Items]

Future Contingent Acquisition Obligation Due in 2016

48.4

^[1]

Future Contingent Acquisition Obligation Due in 2017

70.5

^[1]

Future Contingent Acquisition Obligation Due in 2018

43.0

^[1]

Future Contingent Acquisition Obligation Due in 2019

6.4

^[1]

Future Contingent Acquisition Obligation Due in 2020

5.2

^[1]

Future Contingent Acquisition Obligation Due Thereafter

11.9

^[1]

Future Contingent Acquisition Obligation Due, Total

185.4

^[1]

Redeemable at noncontrolling equity owners discretion

Business Acquisition, Contingent Consideration [Line Items]

Future Contingent Acquisition Obligation Due in 2016

31.0

Total contingent acquisition payments

Business Acquisition, Contingent Consideration [Line Items]

Future Contingent Acquisition Obligation Due in 2016

102.2

Future Contingent Acquisition Obligation Due in 2017

109.7

Future Contingent Acquisition Obligation Due in 2018

56.1

Future Contingent Acquisition Obligation Due in 2019

20.0

Future Contingent Acquisition Obligation Due in 2020

12.7

Future Contingent Acquisition Obligation Due Thereafter

15.0

Future Contingent Acquisition Obligation Due, Total

315.7

Cash compensation expense included in contingent acquisitions

Business Acquisition, Contingent Consideration [Line Items]

Future Contingent Acquisition Obligation Due in 2016

0.2

Future Contingent Acquisition Obligation Due in 2017

0.2

Future Contingent Acquisition Obligation Due in 2018

0.1

Future Contingent Acquisition Obligation Due in 2019

0.1

Future Contingent Acquisition Obligation Due in 2020

0.1

Future Contingent Acquisition Obligation Due Thereafter

0.0

Future Contingent Acquisition Obligation Due, Total

0.7

Total contingent acquisition payments excluding compensation expense

Business Acquisition, Contingent Consideration [Line Items]

Future Contingent Acquisition Obligation Due in 2016

102.0

Future Contingent Acquisition Obligation Due in 2017

109.5

Future Contingent Acquisition Obligation Due in 2018

56.0

Future Contingent Acquisition Obligation Due in 2019

19.9

Future Contingent Acquisition Obligation Due in 2020

12.6

Future Contingent Acquisition Obligation Due Thereafter

15.0

Future Contingent Acquisition Obligation Due, Total

$ 315.0

[1]

Results by Quarter (Unaudited) (Details) - USD ($)
$ / shares in Units, $ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Revenue

$ 2,196.2

$ 1,865.5

$ 1,876.1

$ 1,676.0

$ 2,207.1

$ 1,841.1

$ 1,851.4

$ 1,637.5

$ 7,613.8

$ 7,537.1

$ 7,122.3

Salaries and related expenses

1,235.1

1,202.2

1,205.2

1,215.2

1,266.4

1,195.2

1,170.2

1,188.6

4,857.7

4,820.4

4,545.5

Office and general expenses

504.7

472.1

455.1

453.1

507.6

474.7

484.7

461.1

1,885.0

1,928.1

1,917.9

Restructuring and other reorganization-related (reversals) charges, net

0.0

(0.7)

0.0

(0.1)

0.1

(0.1)

0.7

(0.5)

(0.8)

0.2

60.6

Operating income (loss)

456.4

191.9

215.8

7.8

433.0

171.3

195.8

(11.7)

(871.9)

(788.4)

(598.3)

Other income (expense), net

10.3

^[1]

37.2

^[1]

(0.5)

(0.3)

0.1

0.6

11.2

^[1]

(1.7)

46.7

10.2

32.3

Total (expenses) and other income

(28.6)

^[1]

(52.9)

^[1]

(14.8)

(13.4)

(14.4)

13.8

(27.2)

^[1]

(12.3)

109.7

67.7

130.3

(Benefit of) provision for income taxes

145.4

61.1

77.7

(1.4)

87.9

^[2]

65.0

65.3

(1.7)

282.8

216.5

181.2

Net (loss) income

(282.9)

(78.0)

(123.8)

4.2

(331.3)

(92.8)

(103.7)

22.4

(480.5)

(505.4)

(288.9)

Net (loss) income available to IPG common stockholders

$ 260.3

$ 74.9

$ 121.2

$ (1.8)

$ 308.9

^[2]

$ 89.7

$ 99.4

$ (20.9)

$ 454.6

$ 477.1

$ 259.2

Dividends declared per common share

$ 0.120

$ 0.095

$ 0.48

$ 0.38

$ 0.30

Basic earnings per share

0.65

0.18

0.30

0.00

0.75

0.21

0.24

(0.05)

1.11

1.14

0.62

Diluted earnings per share

$ 0.63

$ 0.18

$ 0.29

$ 0.00

$ 0.73

$ 0.21

$ 0.23

$ (0.05)

$ 1.09

$ 1.12

$ 0.61

[1]	The three months ended December 31, 2015 included pre-tax losses of $12.0 on sales of businesses. The three months ended September 30, 2015 included pre-tax losses of $38.0 on sales of businesses. The three months ended June 30, 2014 included a pre-tax loss of $10.4 related to our early extinguishment of debt.
[2]	The three months ended December 31, 2014 included a tax benefit of $67.6 due to the net reversal of valuation allowances on deferred tax assets in Continental Europe.

Subsequent Events (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares
Subsequent Event [Line Items]
Dividends Payable, Amount Per Share \| $ / shares	$ 0.15
Dividends Payable, Date to be Paid	Mar. 15, 2016
Dividends Payable, Date of Record	Mar. 01, 2016
2016 Share Repurchase Program
Subsequent Event [Line Items]
Share repurchase program, initial authorized amount \| $	$ 300.0