Long-term Debt, Excluding Current Maturities

Long-term Debt

$ 1,624.8

$ 1,625.6

Less: current portion

2.0

2.1

1,622.8

1,623.5

2.25% Notes

Nov. 15, 2017

Debt Instrument, Interest Rate, Effective Percentage

2.25%

2.30%

0.3

299.7

299.6

303.2

^[1]

301.2

^[1]

4.00% Notes

Mar. 15, 2022

Debt Instrument, Interest Rate, Effective Percentage

4.00%

4.13%

2.1

247.9

247.7

255.2

^[1]

255.2

^[1]

3.75% Notes

Feb. 15, 2023

Debt Instrument, Interest Rate, Effective Percentage

3.75%

4.32%

1.2

498.8

495.8

^[1]

499.8

^[1]

4.20% Notes

Apr. 15, 2024

Debt Instrument, Interest Rate, Effective Percentage

4.20%

4.24%

0.8

499.2

499.1

505.9

^[1]

509.8

^[1]

Other notes payable and capitalized leases

79.2

80.4

Redeemable Noncontrolling Interests [Abstract]

$ 79.2

^[1]

$ 80.4

^[1]

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

Credit Facilities (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2015
Debt and Credit Arrangements [Abstract]
Line of Credit Facility, Expiration Date	Dec. 12, 2018
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000.0
Line of Credit Facility, Increase Available	250.0
Line of Credit Facility, Amount Outstanding	$ 200.0

Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net Income Attributable to IPG Common Stockholders	$ 121.2	$ 99.4	$ 119.4	$ 78.5
Weighted Average Number of Shares Outstanding, Basic	410.5	421.1	410.8	421.9
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units	$ 7.1	$ 7.0	$ 6.8	$ 6.6
Weighted Average Number of Shares Outstanding, Diluted	417.6	428.1	417.6	428.5
Earnings Per Share, Basic	$ 0.30	$ 0.24	$ 0.29	$ 0.19
Earnings Per Share, Diluted	$ 0.29	$ 0.23	$ 0.29	$ 0.18

Supplementary Data Accrued Liabilities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2015	Dec. 31, 2014
Accounts Payable, Current [Abstract]
Salaries, benefits and related expenses	$ 356.4	$ 510.6
Office and related expenses	46.1	51.5
Acquisition obligations	65.6	88.1
Interest	17.5	18.3
Restructuring and other reorganization-related	4.0	5.5
Other	114.2	122.0
Accrued liabilities, current	$ 603.8	$ 796.0

Supplementary Data Other Income and Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Other Income and Expenses [Abstract]
Loss on Early Extinguishment of Debt	$ 0	$ (10.4)	$ 0	$ 10.4
(Losses) Gains on Sales of Businesses and Investments	(0.1)	0.3	(0.2)	1.1
Vendor Discounts and Credit Adjustments	0.3	0.2	0.3	1.7
Other Income (Expense), Net	0.3	(1.3)	0.7	(1.9)
Other Nonoperating Income (Expense)	$ 0.5	$ (11.2)	$ 0.8	$ (9.5)

Supplementary Data Share Repurchase Program (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Equity [Abstract]
Number of shares repurchased	4.9	(5.6)
Aggregate cost, including fees	$ 102.0	$ 97.3
Average price per share, including fees	$ 20.87	$ 17.51
Stock Repurchase Program, Authorized Amount	300.0	300.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 341.6

Supplementary Data Redeemable Noncontrolling Interests (Details) (USD $)
In Millions, unless otherwise specified

6 Months Ended

Jun. 30, 2015

Jun. 30, 2014

Beginning Balance

$ 257.4

$ 249.1

(8.3)

(6.8)

Additions

7.9

Redemptions and Other

(22.5)

(2.9)

Redemption Value Adjustments

3.5

^[1]

(0.9)

^[1]

Ending Balance

$ 230.1

$ 246.4

[1]

1In 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, except adjustments as a result of currency translation.

Incentive Compensation Plans Stock-based Compensation Awards (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2015
Share-based Compensation Award [Abstract]
Incentive Compensation Plan Initiation Year	2014
Incentive Compensation Plans
Granted awards	3.5
Stock settled awards
Incentive Compensation Plans
Granted awards	0.7
Weighted Average Grant Date Fair Value	$ 22.12
Performance based awards
Incentive Compensation Plans
Granted awards	2.8
Weighted Average Grant Date Fair Value	$ 20.88
Cash awards
Incentive Compensation Plans
Performance Cash awards granted during the period target value	$ 32.8
Restricted Cash awards granted during the period target value	$ 0.7
Cash awards vesting period	3 years

Restructuring and Other Reorganization-Related Costs 2013 Plan (Details) (2013 Restructuring Plan, USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2015
Restructuring Cost and Reserve
Beginning Liability Balance	$ 7.0
Net Restructuring Reversals	(0.1)
Cash Payments	(2.0)
Foreign Currency Translation Adjustments	(0.2)
Ending Liability Balance	4.7
Severance and termination costs
Restructuring Cost and Reserve
Beginning Liability Balance	4.4
Net Restructuring Reversals	0
Cash Payments	(1.5)
Foreign Currency Translation Adjustments	(0.1)
Ending Liability Balance	2.8
Lease termination costs
Restructuring Cost and Reserve
Beginning Liability Balance	2.6
Net Restructuring Reversals	(0.1)
Cash Payments	(0.5)
Foreign Currency Translation Adjustments	(0.1)
Ending Liability Balance	$ 1.9

Accumulated Other Comprehensive Loss, Net of Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Foreign Currency Translation Adjustment:
Balance at beginning of period			$ (436.3)	$ (243.7)
Other comprehensive (loss) income before reclassifications			(108.3)	25.4
Amount reclassified from accumulated other comprehensive loss, net of tax			(1.2)	(0.9)
Balance at end of period	(545.8)	(219.2)	(545.8)	(219.2)
Available-for-sale Securities:
Balance at beginning of period			0.8	0.4
Other comprehensive (loss) income before reclassifications			0.2	0.2
Amount reclassified from accumulated other comprehensive loss, net of tax			(0.1)	0
Balance at end of period	0.9	0.6	0.9	0.6
Derivative instruments:
Balance at beginning of period			(10.9)	(11.7)
Other comprehensive (loss) income before reclassifications	0	0	0	(0.6)
Amount reclassified from accumulated other comprehensive loss, net of tax			0.6	0.8
Balance at end of period	(10.3)	(11.5)	(10.3)	(11.5)
Defined benefit pension and other postretirement plans:
Balance at beginning of period			(190.3)	(156.2)
Other comprehensive (loss) income before reclassifications			5.5	(0.5)
Amount reclassified from accumulated other comprehensive loss,net of tax			4.2	3.7
Balance at end of period	(180.6)	(153.0)	(180.6)	(153.0)
Total Changes in Accumulated Other Comprehensive Loss, Net of Tax [Abstract]
Balance at beginning of period			(636.7)	(411.2)
Other comprehensive (loss) income before reclassifications			(102.6)	24.5
Amount reclassified from accumulated other comprehensive loss, net of tax	1.9	2.0	3.5	3.6
Balance at end of period	$ (735.8)	$ (383.1)	$ (735.8)	$ (383.1)

Accumulated Other Comprehensive Loss, Net of Tax Reclassification of Accumulated Other Comprehensive Loss (Details) (USD $)
In Millions, unless otherwise specified

3 Months Ended

6 Months Ended

Jun. 30, 2015

Jun. 30, 2014

Jun. 30, 2015

Jun. 30, 2014

Reclassification of Accumulated Other Comprehensive Income [Abstract]

Foreign currency translation adjustments

$ (0.7)

$ 0

$ (1.2)

$ (0.9)

Losses on derivative instruments

0.5

1.0

0.9

Amortization of defined benefit pension and postretirement plans items

3.4

^[1]

2.4

^[1]

6.4

^[1]

5.0

^[1]

Tax effect

(1.3)

(0.9)

(2.7)

(1.4)

Total amount reclassified from accumulated other comprehensive loss, net of tax

$ 1.9

$ 2.0

$ 3.5

$ 3.6

[1]	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 9 for further information.

Employee Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Domestic Pension Plan
Defined Pension and Postretirement Benefit Plans
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	1.5	1.5	3.0	3.1
Expected return on plan assets	(1.9)	(1.8)	(3.8)	(3.7)
Settlements and curtailments	0	0	0	0
Amortization of:
Prior service cost (credit)	0	0	0	0
Unrecognized actuarial losses	2.1	1.6	4.1	3.3
Net periodic cost	1.7	1.3	3.3	2.7
Actual Employer Contributions - Current Fiscal Year			1.9
Estimated Future Employer Contributions - Current Fiscal Year			1.0
Foreign Pension Plans
Defined Pension and Postretirement Benefit Plans
Service cost	2.4	2.4	4.9	4.9
Interest cost	4.7	5.9	9.4	11.8
Expected return on plan assets	(5.2)	(6.2)	(10.3)	(12.4)
Settlements and curtailments	0.2	0	0.2	0
Amortization of:
Prior service cost (credit)	0.1	0.1	0.1	0.1
Unrecognized actuarial losses	1.0	0.8	2.0	1.7
Net periodic cost	3.2	3.0	6.3	6.1
Actual Employer Contributions - Current Fiscal Year			11.5
Estimated Future Employer Contributions - Current Fiscal Year			11.0
Domestic Postretirement Benefit Plan
Defined Pension and Postretirement Benefit Plans
Service cost	0	0	0	0
Interest cost	0.3	0.5	0.7	0.9
Expected return on plan assets	0	0	0	0
Settlements and curtailments	0	0	0	0
Amortization of:
Prior service cost (credit)	0	(0.1)	0	(0.1)
Unrecognized actuarial losses	0	0	0	0
Net periodic cost	$ 0.3	$ 0.4	$ 0.7	$ 0.8

Segment Information Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Financial Data:
Revenue	$ 1,876.1	$ 1,851.4	$ 3,552.1	$ 3,488.9
Operating Income (Loss)	215.8	195.8	223.6	184.1
Interest expense	20.3	22.6	41.2	42.8
Interest income	5.0	6.6	12.2	12.8
Other Nonoperating Income (Expense)	0.5	(11.2)	0.8	(9.5)
Income before income taxes	201.0	168.6	195.4	144.6
Depreciation and amortization of fixed assets and intangible assets	39.5	40.2	78.2	80.7
Capital expenditures	29.6	32.1	49.8	58.7
IAN
Financial Data:
Revenue	1,526.7	1,496.0	2,876.6	2,811.7
Operating Income (Loss)	205.0	184.0	236.6	195.5
Depreciation and amortization of fixed assets and intangible assets	30.2	30.2	59.6	61.7
Capital expenditures	20.4	17.2	32.5	31.1
CMG
Financial Data:
Revenue	349.4	355.4	675.5	677.2
Operating Income (Loss)	41.3	41.3	61.0	58.8
Depreciation and amortization of fixed assets and intangible assets	4.4	4.6	9.0	8.8
Capital expenditures	2.3	3.1	3.4	5.6
Corporate and Other
Financial Data:
Operating Income (Loss)	(30.5)	(29.5)	(74.0)	(70.2)
Depreciation and amortization of fixed assets and intangible assets	4.9	5.4	9.6	10.2
Capital expenditures	$ 6.9	$ 11.8	$ 13.9	$ 22.0

Fair Value Measurements, Recurring and Nonrecurring Basis (Details) (USD $)
In Millions, unless otherwise specified

Jun. 30, 2015

Dec. 31, 2014

Fair Value, Measurements, Recurring | Level 1

$ 357.4

$ 901.4

6.7

6.6

0.5

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

364.6

908.5

3.20%

7.10%

^[1]

Fair Value, Measurements, Recurring | Level 2

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

0.00%

^[1]

Fair Value, Measurements, Recurring | Level 3

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

0.00%

44.9

^[1]

32.8

^[1]

Fair Value, Measurements, Recurring | Fair Value, Total

357.4

901.4

6.7

6.6

0.5

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

364.6

908.5

3.20%

7.10%

44.9

^[1]

32.8

^[1]

Fair Value, Measurements, Nonrecurring | Level 1

Fair Value, Measurements, Nonrecurring | Level 2

1,560.1

1,566.0

Fair Value, Measurements, Nonrecurring | Level 3

79.2

80.4

Fair Value, Measurements, Nonrecurring | Fair Value, Total