The Interpublic Group of Companies, Inc. (IPG) 10-Q 23 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 15, 2014
Document and Entity Information	'	'
Amendment Flag	'false	'
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-Q	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Entity Common Stock, Shares Outstanding	'	418,229,032

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
REVENUE	$1,841.10	$1,700.40	$5,330	$4,999.60
OPERATING EXPENSES:	'	'	'	'
Salaries and related expenses	1,195.20	1,093.60	3,554	3,345.90
Office and general expenses	474.6	465.3	1,420.60	1,379.80
Total operating expenses	1,669.80	1,558.90	4,974.60	4,725.70
OPERATING INCOME	171.3	141.5	355.4	273.9
EXPENSES AND OTHER INCOME:	'	'	'	'
Interest expense	-20.7	-23.7	-63.5	-98
Interest income	7.5	5.8	20.3	18
Other expense, net	-0.6	-46.6	-10.1	-40
Total (expenses) and other income	-13.8	-64.5	-53.3	-120
Income before income taxes	157.5	77	302.1	153.9
Provision for income taxes	65	28.4	128.6	78
Income of consolidated companies	92.5	48.6	173.5	75.9
Equity in net income of unconsolidated affiliates	0.3	0.6	0.6	0.9
NET INCOME	92.8	49.2	174.1	76.8
Net income attributable to noncontrolling interests	-3.1	-0.9	-5.9	-2
NET INCOME ATTRIBUTABLE TO IPG	89.7	48.3	168.2	74.8
Dividends on preferred stock	0	-2.9	0	-8.7
NET INCOME AVAILABLE TO IPG COMMON STOCKHOLDERS	$89.70	$45.40	$168.20	$66.10
Earnings per share available to IPG common stockholders - basic	$0.21	$0.11	$0.40	$0.16
Earnings per share available to IPG common stockholders - diluted	$0.21	$0.11	$0.39	$0.16
Weighted Average Number of Shares Outstanding, Basic	419.2	419.7	421	419.7
Weighted Average Number of Shares Outstanding, Diluted	426.4	426.1	427.2	424.8
Dividends declared per common share	$0.10	$0.08	$0.28	$0.23

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'		'		'		'
NET INCOME	$92.80		$49.20		$174.10		$76.80
OTHER COMPREHENSIVE (LOSS) INCOME	'		'		'		'
Foreign currency translation adjustments	-113.5		24		-89		-89.3
Less: reclassification adjustments recognized in net income	0		0		-0.9		0
Foreign Currency Transaction and Translation Adjustment, Net of Tax	-113.5		24		-89.9		-89.3
Available-for-sale securities:	'		'		'		'
Changes in market value of available-for sale securities	0.2		-0.1		0.4		0.7
Less: recognition of previously unrealized gains included in net income	0		0		0		-1.4
Income tax effect	-0.3		0		-0.3		0.2
Available-for-sale securities, net of tax	-0.1		-0.1		0.1		-0.5
Derivative instruments:	'		'		'		'
Changes in fair value of derivative instruments	0		0		-0.6		0
Less: recognition of previously unrealized losses included in net income	0.5		0.4		1.4		1.3
Income tax effect	-0.2		-0.1		-0.3		-0.5
Derivative instruments, net of tax	0.3		0.3		0.5		0.8
Defined benefit pension and other postretirement plans:	'		'		'		'
Net actuarial losses for the period	0		0		-0.3		0
Less: amortization of unrecognized losses, transition obligation and prior service cost included in net income	2.6	[1]	2.7	[1]	7.6	[1]	8.2	[1]
Other	-0.1		-0.2		-0.3		-0.9
Income tax effect	-1		-0.8		-2.3		-2.8
Defined benefit pension and other postretirement plans, net of tax	1.5		1.7		4.7		4.5
Other comprehensive (loss) income, net of tax	-111.8		25.9		-84.6		-84.5
TOTAL COMPREHENSIVE (LOSS) INCOME	-19		75.1		89.5		-7.7
Less: comprehensive income (loss) attributable to noncontrolling interests	3.4		0.7		5.3		-1.2
COMPREHENSIVE (LOSS) INCOME ATTRIBUTABLE TO IPG	($22.40)		$74.40		$84.20		($6.50)
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 10 for further information.

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
ASSETS:	'		'
Cash and cash equivalents	$896		$1,636.80
Marketable securities	6.4		5.3
Accounts receivable, net of allowance of $64.7 and $64.9, respectively	3,870.90		4,565.40
Expenditures billable to clients	1,725.60		1,536.40
Other current assets	402		340.1
Total current assets	6,900.90		8,084
Furniture, equipment and leasehold improvements, net of accumulated depreciation of $1,086.1 and $1,111.7, respectively	530.2		540
Deferred income taxes	160.6		144
Goodwill	3,686.40		3,629
Other non-current assets	500.3		508
TOTAL ASSETS	11,778.40		12,905
LIABILITIES:	'		'
Accounts payable	5,875		6,914.20
Accrued liabilities	638.8		718.4
Short-term borrowings	128.3		179.1
Current portion of long-term debt	2.2	[1]	353.6	[1]
Total current liabilities	6,644.30		8,165.30
Long-term debt	1,626.80		1,129.80
Deferred compensation	475.8		514.3
Other non-current liabilities	660.3		595.7
TOTAL LIABILITIES	9,407.20		10,405.10
Redeemable noncontrolling interests (see Note 4)	255.3		249.1
STOCKHOLDERS' EQUITY:	'		'
Common stock	53.3		53
Additional paid-in capital	3,024.40		2,975.20
Retained earnings	915.2		864.5
Accumulated other comprehensive loss, net of tax	-495.2		-411.2
Stockholders Equity Subtotal Before Treasury Stock	3,497.70		3,481.50
Less: Treasury stock	-1,414.40		-1,266.30
Total IPG stockholders' equity	2,083.30		2,215.20
Noncontrolling interests	32.6		35.6
TOTAL STOCKHOLDERS' EQUITY	2,115.90		2,250.80
TOTAL LIABILITIES AND EQUITY	11,778.40		12,905
Parentheticals:	'		'
Allowance for Doubtful Accounts Receivable, Current	64.7		64.9
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$1,086.10		$1,111.70
[1]	We included our 6.25% Senior Unsecured Notes due 2014 (the "6.25% Notes") in the current portion of long-term debt on our December 31, 2013 Consolidated Balance Sheet because the 6.25% Notes were scheduled to mature on November 15, 2014. We redeemed the 6.25% Notes prior to their scheduled maturity during the second quarter of 2014.

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
NET INCOME	$174.10	$76.80
Adjustments to reconcile net income to net cash used in operating activities:	'	'
Depreciation and amortization of fixed assets and intangible assets	121.7	117.9
Provision for uncollectible receivables	9	11.4
Amortization of restricted stock and other non-cash compensation	37.9	32.9
Net amortization of bond discounts and deferred financing costs	3.7	5.4
Deferred income tax provision	49.1	28.5
Other	17.1	-7.4
Changes in assets and liabilities, net of acquisitions and dispositions, providing (using) cash:	'	'
Accounts receivable	623	586.9
Expenditures billable to clients	-193.2	-250.9
Other current assets	-65	-38.8
Accounts payable	-1,015.70	-811.5
Accrued liabilities	-107.2	-152.9
Other non-current assets and liabilities	-35	-43.9
Net cash used in operating activities	-381	-430.4
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Capital expenditures	-94.4	-91.6
Acquisitions, including deferred payments, net of cash acquired	-62.9	-48.2
Proceeds from sales of businesses and investments, net of cash sold	14	3.3
Net (purchases) sales and maturities of short-term marketable securities	-0.5	10.8
Other investing activities	1.9	-2.4
Net cash used in investing activities	-141.9	-128.1
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Proceeds from Issuance of Long-term Debt	499.1	0
Purchase of long-term debt	-350.1	-601.2
Repurchase of common stock	-148.1	-280.8
Common stock dividends	-119.9	-94.1
Net (decrease) increase in short term bank borrowings	-44.4	13.3
Distributions to noncontrolling interests	-13.9	-10.4
Acquisition-related payments	-12.7	-27.5
Preferred stock dividends	0	-8.7
Excess tax benefit on share-based compensation	4.9	9.2
Exercise of stock options	11.9	43.6
Other financing activities	-1.6	1
Net cash used in financing activities	-174.8	-955.6
Effect of foreign exchange rate changes on cash and cash equivalents	-43.1	-61.4
Net decrease in cash and cash equivalents	-740.8	-1,575.50
Cash and cash equivalents at beginning of period	1,636.80	2,574.80
Cash and cash equivalents at end of period	$896	$999.30

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Preferred Stock	Common Stock, Shares	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss, Net of Tax	Treasury Stock	Total IPG Stockholders' Equity	Noncontrolling Interests
In Millions	USD ($)	USD ($)		USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
Balance at Dec. 31, 2012	$2,456.60	$221.50	'	$48.80	$2,465.40	$738.30	($288)	($765.40)	$2,420.60	$36
Balance, Common Stock Shares at Dec. 31, 2012	'	'	492	'	'	'	'	'	'	'
Net income	76.8	'	'	'	'	74.8	'	'	74.8	2
Other comprehensive loss	-84.5	'	'	'	'	'	-81.3	'	-81.3	-3.2
Reclassifications related to redeemable noncontrolling interests	4.9	'	'	'	'	'	'	'	'	4.9
Distributions to noncontrolling interests	-10.4	'	'	'	'	'	'	'	'	-10.4
Change in redemption value of redeemable noncontrolling interests	0.6	'	'	'	'	0.6	'	'	0.6	'
Repurchase of common stock	-280.8	'	'	'	'	'	'	-280.8	-280.8	'
Common stock dividends	-94.1	'	'	'	'	-94.1	'	'	-94.1	'
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	'	'	1.7	198.3	'	'	'	200	'
Capped call transaction	0	'	'	'	19.1	'	'	-19.1	0	'
Stock-based compensation, shares	'	'	2.4	'	'	'	'	'	'	'
Stock-based compensation	37.6	'	'	0.4	37.2	'	'	'	37.6	'
Exercise of stock options, shares	'	'	4.7	'	'	'	'	'	'	'
Exercise of stock options	44.1	'	'	0.5	43.6	'	'	'	44.1	'
Shares withheld for taxes, shares	'	'	-1.5	'	'	'	'	'	'	'
Shares withheld for taxes	-20	'	'	-0.2	-19.8	'	'	'	-20	'
Excess tax benefit from stock-based compensation	8.5	'	'	'	8.5	'	'	'	8.5	'
Other	2.9	'	'	'	1.8	-0.5	'	'	1.3	-1.6
Balance at Sep. 30, 2013	2,333.50	221.5	'	51.2	2,754.10	710.4	-369.3	-1,065.30	2,302.60	30.9
Balance, Common Stock Shares at Sep. 30, 2013	'	'	514.5	'	'	'	'	'	'	'
Balance at Dec. 31, 2013	2,250.80	'	'	53	2,975.20	864.5	-411.2	-1,266.30	2,215.20	35.6
Balance, Common Stock Shares at Dec. 31, 2013	'	'	532.3	'	'	'	'	'	'	'
Net income	174.1	'	'	'	'	168.2	'	'	168.2	5.9
Other comprehensive loss	-84.6	'	'	'	'	'	-84	'	-84	-0.6
Reclassifications related to redeemable noncontrolling interests	6.7	'	'	'	'	'	'	'	'	6.7
Distributions to noncontrolling interests	-13.9	'	'	'	'	'	'	'	'	-13.9
Change in redemption value of redeemable noncontrolling interests	3	'	'	'	'	3	'	'	3	'
Repurchase of common stock	-148.1	'	'	'	'	'	'	-148.1	-148.1	'
Common stock dividends	-119.9	'	'	'	'	-119.9	'	'	-119.9	'
Stock-based compensation, shares	'	'	3.3	'	'	'	'	'	'	'
Stock-based compensation	51.1	'	'	0.3	50.8	'	'	'	51.1	'
Exercise of stock options, shares	'	'	1	'	'	'	'	'	'	'
Exercise of stock options	12	'	'	0.1	11.9	'	'	'	12	'
Shares withheld for taxes, shares	'	'	-0.8	'	'	'	'	'	'	'
Shares withheld for taxes	-14.8	'	'	-0.1	-14.7	'	'	'	-14.8	'
Excess tax benefit from stock-based compensation	4.9	'	'	'	4.9	'	'	'	4.9	'
Other	-5.4	'	'	'	-3.7	-0.6	'	'	-4.3	-1.1
Balance at Sep. 30, 2014	$2,115.90	'	'	$53.30	$3,024.40	$915.20	($495.20)	($1,414.40)	$2,083.30	$32.60
Balance, Common Stock Shares at Sep. 30, 2014	'	'	535.8	'	'	'	'	'	'	'

Basis_of_Presentation_Notes

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2014
Basis of Presentation [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The unaudited Consolidated Financial Statements have been prepared by The Interpublic Group of Companies, Inc. and its subsidiaries (the “Company,” “IPG,” “we,” “us” or “our”) in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting interim financial information on Form 10-Q. Accordingly, they do not include certain information and disclosures required for complete financial statements. The preparation of financial statements in conformity with U.S. GAAP requires us to make judgments, assumptions and estimates that affect the amounts reported and disclosed. Actual results could differ from these estimates and assumptions. The consolidated results for interim periods are not necessarily indicative of results for the full year and should be read in conjunction with our 2013 Annual Report on Form 10-K.
	In the opinion of management, these unaudited Consolidated Financial Statements include all adjustments, consisting only of normal and recurring adjustments necessary for a fair statement of the information for each period contained therein.

Debt_and_Credit_Arrangements_N

Debt and Credit Arrangements (Notes)	9 Months Ended
	Sep. 30, 2014
Debt and Credit Arrangements [Abstract]	'
Debt and Credit Arrangements	'
	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	September 30,				December 31,
		Interest Rate	2014				2013
			Book		Fair		Book		Fair
			Value		Value 1		Value		Value 1
	6.25% Senior Unsecured Notes due 2014	6.29%	$	0	$	0	$	351.3	$	365.6
	2.25% Senior Notes due 2017 (less unamortized	2.30%	299.5		300.8		299.4		293
	discount of $0.5)
	4.00% Senior Notes due 2022 (less unamortized	4.13%	247.7		254.7		247.4		241.6
	discount of $2.3)
	3.75% Senior Notes due 2023 (less unamortized	4.32%	498.7		496.2		498.6		467.3
	discount of $1.3)
	4.20% Senior Notes due 2024 (less unamortized	4.24%	499.1		506.7		0		0
	discount of $0.9)
	Other notes payable and capitalized leases		84		86.6		86.7		87.8
	Total long-term debt		1,629.00				1,483.40
	Less: current portion 2		2.2				353.6
	Long-term debt, excluding current portion		$	1,626.80			$	1,129.80
	1	See Note 12 for information on the fair value measurement of our long-term debt.
	2	We included our 6.25% Senior Unsecured Notes due 2014 (the "6.25% Notes") in the current portion of long-term debt on our December 31, 2013 Consolidated Balance Sheet because the 6.25% Notes were scheduled to mature on November 15, 2014. We redeemed the 6.25% Notes prior to their scheduled maturity during the second quarter of 2014.
	Debt Transactions
	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 unaudited Consolidated Balance Sheet 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 below.
	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.
	6.25% Senior Unsecured Notes due 2014
	In May 2014, we redeemed all $350.0 in aggregate principal amount of 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, which was primarily due to a redemption premium paid to noteholders. The loss on early extinguishment of debt was recorded in other expense, net within our unaudited Consolidated Statement of Operations.
	Credit Agreements
	We maintain a committed corporate credit facility (the "Credit Agreement") and uncommitted lines of credit to increase our financial flexibility. The Credit Agreement is a revolving facility, expiring in December 2018, 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.
	We were in compliance with all of our covenants in the Credit Agreement as of September 30, 2014.

Earnings_Per_Share_Notes

Earnings Per Share (Notes)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share [Text Block]	'
	Earnings Per Share
	The following sets forth basic and diluted earnings per common share available to IPG common stockholders.
		Three months ended								Nine months ended
		September 30,								September 30,
		2014				2013				2014		2013
	Net income available to IPG common stockholders - basic and diluted	$	89.7			$	45.4			$	168.2	$	66.1
	Weighted-average number of common shares outstanding - basic	419.2		419.7			421		419.7
	Add: Effect of dilutive securities
	Restricted stock, stock options and other equity awards	7.2		6.4			6.2		5.1
	Weighted-average number of common shares outstanding - diluted	426.4		426.1			427.2		424.8
	Earnings per share available to IPG common stockholders - basic	$	0.21			$	0.11			$	0.4	$	0.16
	Earnings per share available to IPG common stockholders - diluted	$	0.21			$	0.11			$	0.39	$	0.16
	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.
		Three months ended						Nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
	4.75% Notes 1	0			0			0			4.4
	Preferred stock 2	0			17.3			0			17.3
	Total	0			17.3			0			21.7
	Securities excluded from the diluted earnings per share calculation
	because the exercise price was greater than the average market price:
	Stock options 3	0			0			0			0.2
	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, the potentially dilutive shares are pro-rated based on the period they were outstanding but were antidilutive.
	2	We converted all of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock into common stock in October 2013.
	3	These options are 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

Acquisitions (Notes)	9 Months Ended
	Sep. 30, 2014
Acquisitions [Abstract]	'
Business Combination Disclosure [Text Block]	'
	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, foreign currency exchange rates and other factors.
	During the first nine months of 2014, we completed six acquisitions, consisting of a global digital agency, a full service digital agency in the United States, a healthcare agency in the United Kingdom, a digital public relations agency based in Sweden, a digital and traditional creative agency in Germany and a search marketing agency based in the Netherlands. Of our six acquisitions, four were included in the Integrated Agency Networks (“IAN”) operating segment and two were included in the Constituency Management Group ("CMG") operating segment. During the first nine months of 2014, we recorded approximately $137.0 of goodwill and intangible assets related to these acquisitions.
	During the first nine months of 2013, we completed eight acquisitions, including a full-service digital agency in India, a public relations consultancy in India and a mobile marketing agency in Australia. Of our eight acquisitions, seven were included in the IAN operating segment and one was included in the CMG operating segment. During the first nine months of 2013, we recorded approximately $67.0 of goodwill and intangible assets related to those acquisitions.
	The results of operations of our acquired companies were included in our consolidated results from the closing date of each acquisition. Details of cash paid for current and prior years' acquisitions are listed below.
		Nine months ended
		September 30,
		2014			2013
	Cost of investment: current-year acquisitions	$	87.2		$	51.9
	Cost of investment: prior-year acquisitions	13.3			28.5
	Less: net cash acquired	(24.9		)	(4.7		)
	Total cost of investment	75.6			75.7
	Operating expense 1	1.8			1.6
	Total cash paid for acquisitions 2	$	77.4		$	77.3
	1	Represents cash payments made that were either in excess of the contractual value or contingent upon the future employment of the former owners of the acquired companies.
	2	Of the total cash paid, $12.7 and $27.5 for the nine months ended September 30, 2014, and 2013, respectively, are classified under the financing section of the unaudited Consolidated Statements of Cash Flows within acquisition-related payments. These amounts relate to increases in our ownership interests in our consolidated subsidiaries, as well as deferred payments for acquisitions that closed on or after January 1, 2009. Of the total cash paid, $62.9 and $48.2 for the nine months ended September 30, 2014, and 2013, respectively, are classified under the investing section of the unaudited Consolidated Statements of Cash Flows within acquisitions, including deferred payments, net of cash acquired. These amounts relate to initial payments for new transactions and deferred payments for acquisitions that closed prior to January 1, 2009.
	Many of our acquisitions also include provisions under which the noncontrolling equity owners may require us to purchase additional interests in a subsidiary at their discretion. The following table presents changes in our redeemable noncontrolling interests.
		Nine months ended
		September 30,
		2014			2013
	Balance at beginning of period	$	249.1		$	227.2
	Change in related noncontrolling interests balance	(6.7		)	(4.9		)
	Changes in redemption value of redeemable noncontrolling interests:
	Additions	22			12.5
	Redemptions and other	(4.5		)	(2.1		)
	Redemption value adjustments 1	(4.6		)	(3.1		)
	Balance at end of period	$	255.3		$	229.6
	1	Redeemable noncontrolling interests are reported at their estimated redemption value in each reporting period, but not less than their initial fair value. Any adjustment to the redemption value impacts retained earnings or additional paid-in capital, except adjustments as a result of currency translation.

Supplementary_Data_Notes

Supplementary Data (Notes)	9 Months Ended
	Sep. 30, 2014
Supplementary Data [Abstract]	'
Supplementary Data	'
	Accrued Liabilities
	The following table presents the components of accrued liabilities.
		September 30,			December 31,
		2014			2013
	Salaries, benefits and related expenses	$	410.7		$	467.2
	Office and related expenses	50.3			56.9
	Acquisition obligations	57			12.8
	Interest	17.2			16
	Restructuring and other reorganization-related	7.2			46.7
	Other	96.4			118.8
	Total accrued liabilities	$	638.8		$	718.4
	Other Expense, Net
	Results of operations for the three and nine months ended September 30, 2014 and 2013, include certain items that are not directly associated with our revenue-producing operations.
		Three months ended						Nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
	Loss on early extinguishment of debt	$	0		$	(45.2	)	$	(10.4	)	$	(45.2	)
	Gains (losses) on sales of businesses and investments	0.1			$	(0.8	)	1.2			1.9
	Vendor discounts and credit adjustments	0.3			0.1			2			0.6
	Other (expense) income, net	(1.0		)	(0.7		)	(2.9		)	2.7
	Total other expense, net	$	(0.6	)	$	(46.6	)	$	(10.1	)	$	(40.0	)
	Loss on Early Extinguishment of Debt – During the nine months ended September 30, 2014, we recorded a charge of $10.4 related to the redemption of our 6.25% Notes. See Note 2 to the unaudited Consolidated Financial Statements for further information. During the nine months ended September 30, 2013, we recorded a charge of $45.2 related to the redemption of our 10.00% Senior Unsecured Notes due 2017.
	Sales of Businesses and Investments – During the nine months ended September 30, 2014, we recognized gains from the sale of a business within our IAN segment and the sale of investments in Rabbi Trusts. During the nine months ended September 30, 2013, the gains on sales of businesses and investments related to a gain recognized 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 was partially offset by a loss recognized in the third quarter of 2013 from the sale of a business in the United Kingdom within our IAN segment.
	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 (Expense) Income, net – During the nine months ended September 30, 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 the nine months ended September 30, 2013, other 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 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, our 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").
	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 2013 and 2014 Share Repurchase Programs for the nine months ended September 30, 2014 and 2013.
		Nine months ended
		September 30,
		2014			2013
	Number of shares repurchased	8.3			19.9
	Aggregate cost, including fees	$	148.1		$	280.8
	Average price per share, including fees	$	17.91		$	14.12
	As of September 30, 2014, $270.6 remains available for repurchase under the 2014 Share Repurchase Programs. The 2014 Share Repurchase Program has no expiration date. As of September 30, 2014, we have fully utilized the 2013 Share Repurchase Program.

Income_Taxes_Notes

Income Taxes (Notes)	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	For the three and nine months ended September 30, 2014, our effective income tax rate of 41.3% and 42.6%, respectively, was negatively impacted primarily by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances.
	We have various tax years under examination by tax authorities 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 $30.0 and $40.0 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.
	We are effectively settled with respect to U.S. income tax audits for 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.

Incentive_Compensation_Plans_N

Incentive Compensation Plans (Notes)	9 Months Ended
	Sep. 30, 2014
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]	'
Incentive Compensation Plans	'
	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. The 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. A committee of the Board of Directors may grant performance cash awards to any eligible employee; however, no employee can receive more than $10.0 during a performance period.
	We issued the following stock-based awards under the 2009 PIP and 2014 PIP during the nine months ended September 30, 2014.
		Awards	Weighted-average
			grant-date fair value
			(per award)
	Stock-settled awards	1.2	$	17.73
	Performance-based awards	3.5	$	16.56
	Total stock-based compensation awards	4.7
	During the nine months ended September 30, 2014, the Compensation Committee granted performance cash awards under the 2009 PIP and 2014 PIP with a total target value of $31.4 and $1.5, respectively, and restricted cash awards with a total target value of $4.8 and $0.8, respectively. Cash awards are expensed over the vesting period, typically three years.

Restructuring_and_Other_Reorga

Restructuring and Other Reorganization-Related Costs (Notes)	9 Months Ended
	Sep. 30, 2014
Restructuring and Other Reorganization-Related Costs [Abstract]	'
Restructuring and Related Activities Disclosure [Text Block]	'
	Restructuring and Other Reorganization-Related Liabilities
	In the fourth quarter of 2013, the Company implemented a cost savings initiative (the "2013 Plan") to better align our cost structure with our revenue, primarily in Continental Europe. During the nine months ended September 30, 2014, we recorded $0.2 of net reversals related to the 2013 Plan, which was included in office and general expenses within our unaudited Consolidated Statements of Operations. 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.
		31-Dec-13		Net Restructuring (Reversals) Charges			Cash Payments			Foreign Currency Translation Adjustments			30-Sep-14
	Severance and termination costs	$	46.5	$	(0.3	)	$	(39.5	)	$	(0.3	)	$	6.4
	Lease termination costs	3.9		0.1			(1.2		)	(0.1		)	2.7
	Other exit costs	0.5		0			(0.5		)	0			0
	Total	$	50.9	$	(0.2	)	$	(41.2	)	$	(0.4	)	$	9.1
	Net restructuring reversals related to the 2013 Plan for the nine months ended September 30, 2014 were comprised of net reversals of approximately $0.2 at CMG.
	Prior Restructuring Plans
	The 2007, 2003 and 2001 restructuring plans (the "Prior Restructuring Plans") with current quarter activity included net charges that are adjustments primarily resulting from changes in management’s estimates relating to sublease rental income assumptions. For the nine months ended September 30, 2014, the Prior Restructuring Plans incurred net restructuring and other reorganization-related charges of $0.3. As of September 30, 2014, the remaining liability for the Prior Restructuring Plans was $1.2.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss, Net of Tax (Notes)	9 Months Ended
	Sep. 30, 2014
Accumulated Other Comprehensive Income [Abstract]	'
Comprehensive Income (Loss) Note [Text Block]	'
	Accumulated Other Comprehensive Loss, Net of Tax
	The following tables present 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	(88.4		)	0.4			(0.6		)	(0.6		)	(89.2		)
	Amount reclassified from accumulated other comprehensive loss, net of tax	(0.9		)	(0.3		)	1.1			5.3			5.2
	Balance as of September 30, 2014	$	(333.0	)	$	0.5		$	(11.2	)	$	(151.5	)	$	(495.2	)
		Foreign Currency Translation Adjustments			Available-for-Sale Securities			Derivative Instruments			Defined Benefit Pension and Other Postretirement Plans			Total
	Balance as of December 31, 2012	$	(130.1	)	$	0.8		$	(12.7	)	$	(146.0	)	$	(288.0	)
	Other comprehensive (loss) income before reclassifications	(86.1		)	0.7			0			(0.9		)	(86.3		)
	Amount reclassified from accumulated other comprehensive loss, net of tax	0			(1.2		)	0.8			5.4			5
	Balance as of September 30, 2013	$	(216.2	)	$	0.3		$	(11.9	)	$	(141.5	)	$	(369.3	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax for the three and nine months ended September 30, 2014 and 2013 are as follows:
		Three months ended						Nine months ended						Affected Line Item in the Consolidated Statements of Operations
		September 30,						September 30,
		2014			2013			2014			2013
	Foreign currency translation adjustments	$	0		$	0		$	(0.9	)	$	0		Other expense, net
	Gains on available-for-sale securities	0			0			0			(1.4		)	Other expense, net
	Losses on derivative instruments	0.5			0.4			1.4			1.3			Interest expense
	Amortization of defined benefit pension and postretirement plans items 1	2.6			2.7			7.6			8.2
	Tax effect	(1.5		)	(0.9		)	(2.9		)	(3.1		)	Provision for income taxes
	Total amount reclassified from accumulated other comprehensive loss, net of tax	$	1.6		$	2.2		$	5.2		$	5
	1	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 10 for further information.

Employee_Benefits_Notes

Employee Benefits (Notes)	9 Months Ended
	Sep. 30, 2014
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Employee Benefits	'
	Employee Benefits
	We have a defined benefit pension plan (the “Domestic Pension Plan”) that covers certain U.S. employees. 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. Certain immaterial foreign pension and postretirement benefit plans have been excluded from the table below.
	The components of net periodic cost 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
	Three months ended September 30,	2014			2013			2014			2013			2014			2013
	Service cost	$	0		$	0		$	3		$	2.6		$	0		$	0.1
	Interest cost	1.5			1.4			6			5.3			0.4			0.4
	Expected return on plan assets	(1.8		)	(1.9		)	(6.4		)	(4.7		)	0			0
	Settlements and curtailments	0			0			0.1			0			0			0
	Amortization of:
	Prior service cost (credit)	0			0			0			0.1			0			(0.1		)
	Unrecognized actuarial losses	1.7			2			0.9			0.7			0			0
	Net periodic cost	$	1.4		$	1.5		$	3.6		$	4		$	0.4		$	0.4
		Domestic Pension Plan						Foreign Pension Plans						Domestic
														Postretirement Benefit Plan
	Nine months ended September 30,	2014			2013			2014			2013			2014			2013
	Service cost	$	0		$	0		$	7.9		$	7.7		$	0		$	0.1
	Interest cost	4.6			4.1			17.8			15.9			1.3			1.2
	Expected return on plan assets	(5.5		)	(5.8		)	(18.8		)	(14.3		)	0			0
	Settlements and curtailments	0			0			0.1			0			0			0
	Amortization of:
	Prior service cost (credit)	0			0			0.1			0.2			(0.1		)	(0.1		)
	Unrecognized actuarial losses	5			6			2.6			2.1			0			0
	Net periodic cost	$	4.1		$	4.3		$	9.7		$	11.6		$	1.2		$	1.2
	During the nine months ended September 30, 2014, we contributed $2.1 and $17.8 of cash to our domestic and foreign pension plans, respectively. For the remainder of 2014, we expect to contribute approximately $1.0 and $7.0 of cash to our domestic and foreign pension plans, respectively.

Segment_Information_Notes

Segment Information (Notes)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Reporting Disclosure	'
	Segment Information
	We have two reportable segments, IAN and CMG. IAN is comprised of McCann Worldgroup, FCB (Foote, Cone & Belding), Lowe & Partners, 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. The profitability measure employed by our chief operating decision maker for allocating resources to operating divisions and assessing operating division performance is segment operating income (loss). The segment information is presented consistently with the basis described in our 2013 Annual Report on Form 10-K, except that segment operating income (loss) for the three and nine months ended September 30, 2014, and 2013, respectively, includes the impact of net restructuring and other reorganization-related charges (reversals). See Note 8 for further information on net restructuring and other reorganization-related liabilities.
	Summarized financial information concerning our reportable segments is shown in the following table.
		Three months ended						Nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
	Revenue:
	IAN	$	1,464.60		$	1,370.90		$	4,276.30		$	4,047.70
	CMG	376.5			329.5			1,053.70			951.9
	Total	$	1,841.10		$	1,700.40		$	5,330.00		$	4,999.60
	Segment operating income (loss):
	IAN	$	165.5		$	119.9		$	361		$	266.5
	CMG	47			39.7			105.8			88.3
	Corporate and other	(41.2		)	(18.1		)	(111.4		)	(80.9		)
	Total	171.3			141.5			355.4			273.9
	Interest expense	(20.7		)	(23.7		)	(63.5		)	(98.0		)
	Interest income	7.5			5.8			20.3			18
	Other expense, net	(0.6		)	(46.6		)	(10.1		)	(40.0		)
	Income before income taxes	$	157.5		$	77		$	302.1		$	153.9
	Depreciation and amortization of fixed assets and intangible assets:
	IAN	$	31		$	32.9		$	92.7		$	95.4
	CMG	4.9			3.9			13.7			11.6
	Corporate and other	5.1			3.7			15.3			10.9
	Total	$	41		$	40.5		$	121.7		$	117.9
	Capital expenditures:
	IAN	$	20.9		$	24.5		$	52		$	48
	CMG	2.6			2.4			8.2			6.5
	Corporate and other	12.2			17.9			34.2			37.1
	Total	$	35.7		$	44.8		$	94.4		$	91.6
		September 30,			December 31,
		2014			2013
	Total assets:
	IAN	$	10,689.40		$	11,425.10
	CMG	1,311.50			1,203.80
	Corporate and other	(222.5		)	276.1
	Total	$	11,778.40		$	12,905.00

Fair_Value_Measurements_Notes

Fair Value Measurements (Notes)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	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 the nine months ended September 30, 2014. The following tables present information about our financial instruments measured at fair value on a recurring basis as of September 30, 2014, and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		September 30, 2014												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	470.5		$	0		$	0		$	470.5		Cash and cash equivalents
	Short-term marketable securities	6.4			0			0			6.4			Marketable securities
	Long-term investments	0.5			0			0			0.5			Other non-current assets
	Total	$	477.4		$	0		$	0		$	477.4
	As a percentage of total assets	4.1		%	0		%	0		%	4.1		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	28.8		$	28.8
		December 31, 2013												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	761.2		$	0		$	0		$	761.2		Cash and cash equivalents
	Short-term marketable securities	5.3			0			0			5.3			Marketable securities
	Long-term investments	1.6			0			0			1.6			Other non-current assets
	Total	$	768.1		$	0		$	0		$	768.1
	As a percentage of total assets	6		%	0		%	0		%	6		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	27		$	27
	1	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 for the three and nine months ended September 30, 2014.
		Three months ended						Nine months ended
		September 30,						September 30,
	Liabilities	2014			2013			2014			2013
	Mandatorily redeemable noncontrolling interests -	$	28.7		$	25.7		$	27		$	25.3
	Balance at beginning of period
	Level 3 additions	0			0			2.5			1
	Level 3 reductions	0			0			(0.6		)	(0.9		)
	Realized losses/(gains) included in net income	0.1			0.3			(0.1		)	0.6
	Mandatorily redeemable noncontrolling interests -	$	28.8		$	26		$	28.8		$	26
	Balance at end of period
	Realized losses/(gains) included in net income for mandatorily redeemable noncontrolling interests are reported as a component of interest expense in the unaudited Consolidated Statements of Operations.
	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 September 30, 2014, and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		30-Sep-14												December 31, 2013
		Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Total long-term debt	$	0		$	1,558.40		$	86.6		$	1,645.00		$	0	$	1,367.50	$	87.8	$	1,455.30
	Our long-term debt comprises 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 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. Thus, 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 Assets and Liabilities that are Measured at Fair Value on a Recurring Basis
	Certain non-financial assets and liabilities are measured at fair value on a recurring basis, primarily accrued restructuring charges.
	Non-financial Assets and Liabilities that are Measured at Fair Value on a Nonrecurring Basis
	Certain non-financial assets and liabilities are measured at fair value on a nonrecurring basis, primarily goodwill, intangible assets, and property, plant 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.

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	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.  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.
	Guarantees
	As discussed in our 2013 Annual Report on Form 10-K, 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 $564.0 and $588.1 as of September 30, 2014, and December 31, 2013, respectively, and the amount of parent company guarantees primarily relating to credit facilities was $324.8 and $279.6 as of September 30, 2014, and December 31, 2013, respectively.

Recent_Accounting_Standards_No

Recent Accounting Standards (Notes)	9 Months Ended
	Sep. 30, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recent Accounting Standards	'
	Recent Accounting Standards
	Going Concern
	In August 2014, the Financial Accounting Standards Board (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 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.
	Share-Based Payments with Performance Targets
	In June 2014, the FASB issued amended guidance which requires that a performance target that affects vesting, and that could be achieved after the requisite service period, be treated as a performance condition. This amended guidance will be effective for us beginning January 1, 2016 and can be either applied prospectively or retrospectively. As such, the performance target should not be reflected in estimating the grant date fair value of the award. We are currently assessing the impact the adoption of the amended guidance will have on our Consolidated Financial Statements.
	Revenue Recognition
	In May 2014, the FASB issued amended guidance on revenue recognition, which will be effective for us beginning January 1, 2017 and can be applied retrospectively or as a cumulative effect adjustment as of the date of adoption. Early adoption is not permitted. The amended guidance requires entities 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. We are currently assessing the impact the adoption of the amended guidance will have on our Consolidated Financial Statements.
	Discontinued Operations
	In April 2014, the FASB issued amended guidance which changes the criteria for reporting a discontinued operation, which will be effective for us beginning January 1, 2015 and applied prospectively. Early adoption is permitted, but only for disposals or classifications of held for sale that have not been reported in financial statements previously issued or available for issuance. The amended guidance limits reporting on discontinued operations involving disposals of an entity's components that represent strategic shifts that have (or will have) a major effect on an entity’s operations and financial results. The amended guidance also expands the definition of a discontinued operation to include disposals of equity method investments and a business or nonprofit activity that, on acquisition, meets the criteria to be classified as held for sale. The amended guidance also requires enhanced disclosure requirements related to discontinued operations as well as additional disclosures regarding individually significant disposals that do not qualify for discontinued operations reporting. We early adopted the amended guidance for the quarter ended June 30, 2014. The adoption of this amended guidance did not have a significant impact on our unaudited Consolidated Financial Statements.
	Unrecognized Tax Benefits
	In July 2013, the FASB issued amended guidance on the presentation of unrecognized tax benefits when a net operating loss carryforward, a similar tax loss or a tax credit carryforward exists at the reporting date. The amended guidance requires an entity to present unrecognized tax benefits as a reduction to the deferred tax assets created by net operating losses, similar tax losses or tax credits that occur in the same taxing jurisdiction. To the extent that the unrecognized tax benefit exceeds these losses or credits, it shall be presented as a liability. We adopted the amended guidance as of December 31, 2013. The adoption of this amended guidance did not have a significant impact on our Consolidated Financial Statements.

Debt_and_Credit_Arrangements_T

Debt and Credit Arrangements (Tables)	9 Months Ended
	Sep. 30, 2014
Debt and Credit Arrangements [Abstract]	'
Summary of Carrying Amounts and Fair Values of Long-term Debt	'
	A summary of the carrying amounts and fair values of our long-term debt is listed below.
		Effective	September 30,				December 31,
		Interest Rate	2014				2013
			Book		Fair		Book		Fair
			Value		Value 1		Value		Value 1
	6.25% Senior Unsecured Notes due 2014	6.29%	$	0	$	0	$	351.3	$	365.6
	2.25% Senior Notes due 2017 (less unamortized	2.30%	299.5		300.8		299.4		293
	discount of $0.5)
	4.00% Senior Notes due 2022 (less unamortized	4.13%	247.7		254.7		247.4		241.6
	discount of $2.3)
	3.75% Senior Notes due 2023 (less unamortized	4.32%	498.7		496.2		498.6		467.3
	discount of $1.3)
	4.20% Senior Notes due 2024 (less unamortized	4.24%	499.1		506.7		0		0
	discount of $0.9)
	Other notes payable and capitalized leases		84		86.6		86.7		87.8
	Total long-term debt		1,629.00				1,483.40
	Less: current portion 2		2.2				353.6
	Long-term debt, excluding current portion		$	1,626.80			$	1,129.80
	1	See Note 12 for information on the fair value measurement of our long-term debt.
	2	We included our 6.25% Senior Unsecured Notes due 2014 (the "6.25% Notes") in the current portion of long-term debt on our December 31, 2013 Consolidated Balance Sheet because the 6.25% Notes were scheduled to mature on November 15, 2014. We redeemed the 6.25% Notes prior to their scheduled maturity during the second quarter of 2014.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Schedule of Earnings Per Share, Basic and Diluted	'
	The following sets forth basic and diluted earnings per common share available to IPG common stockholders.
		Three months ended								Nine months ended
		September 30,								September 30,
		2014				2013				2014		2013
	Net income available to IPG common stockholders - basic and diluted	$	89.7			$	45.4			$	168.2	$	66.1
	Weighted-average number of common shares outstanding - basic	419.2		419.7			421		419.7
	Add: Effect of dilutive securities
	Restricted stock, stock options and other equity awards	7.2		6.4			6.2		5.1
	Weighted-average number of common shares outstanding - diluted	426.4		426.1			427.2		424.8
	Earnings per share available to IPG common stockholders - basic	$	0.21			$	0.11			$	0.4	$	0.16
	Earnings per share available to IPG common stockholders - diluted	$	0.21			$	0.11			$	0.39	$	0.16
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	'
	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.
		Three months ended						Nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
	4.75% Notes 1	0			0			0			4.4
	Preferred stock 2	0			17.3			0			17.3
	Total	0			17.3			0			21.7
	Securities excluded from the diluted earnings per share calculation
	because the exercise price was greater than the average market price:
	Stock options 3	0			0			0			0.2
	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, the potentially dilutive shares are pro-rated based on the period they were outstanding but were antidilutive.
	2	We converted all of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock into common stock in October 2013.
	3	These options are 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_Tables

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Cash Paid For Current And Prior Years' Acquisitions	'
	Details of cash paid for current and prior years' acquisitions are listed below.
		Nine months ended
		September 30,
		2014			2013
	Cost of investment: current-year acquisitions	$	87.2		$	51.9
	Cost of investment: prior-year acquisitions	13.3			28.5
	Less: net cash acquired	(24.9		)	(4.7		)
	Total cost of investment	75.6			75.7
	Operating expense 1	1.8			1.6
	Total cash paid for acquisitions 2	$	77.4		$	77.3
	1	Represents cash payments made that were either in excess of the contractual value or contingent upon the future employment of the former owners of the acquired companies.
	2	Of the total cash paid, $12.7 and $27.5 for the nine months ended September 30, 2014, and 2013, respectively, are classified under the financing section of the unaudited Consolidated Statements of Cash Flows within acquisition-related payments. These amounts relate to increases in our ownership interests in our consolidated subsidiaries, as well as deferred payments for acquisitions that closed on or after January 1, 2009. Of the total cash paid, $62.9 and $48.2 for the nine months ended September 30, 2014, and 2013, respectively, are classified under the investing section of the unaudited Consolidated Statements of Cash Flows within acquisitions, including deferred payments, net of cash acquired. These amounts relate to initial payments for new transactions and deferred payments for acquisitions that closed prior to January 1, 2009.
Redeemable Noncontrolling Interests	'
	The following table presents changes in our redeemable noncontrolling interests.
		Nine months ended
		September 30,
		2014			2013
	Balance at beginning of period	$	249.1		$	227.2
	Change in related noncontrolling interests balance	(6.7		)	(4.9		)
	Changes in redemption value of redeemable noncontrolling interests:
	Additions	22			12.5
	Redemptions and other	(4.5		)	(2.1		)
	Redemption value adjustments 1	(4.6		)	(3.1		)
	Balance at end of period	$	255.3		$	229.6
	1	Redeemable noncontrolling interests are reported at their estimated redemption value in each reporting period, but not less than their initial fair value. Any adjustment to the redemption value impacts retained earnings or additional paid-in capital, except adjustments as a result of currency translation.

Supplementary_Data_Tables

Supplementary Data (Tables)	9 Months Ended
	Sep. 30, 2014
Supplementary Data [Abstract]	'
Schedule of Accrued Liabilities	'
	The following table presents the components of accrued liabilities.
		September 30,			December 31,
		2014			2013
	Salaries, benefits and related expenses	$	410.7		$	467.2
	Office and related expenses	50.3			56.9
	Acquisition obligations	57			12.8
	Interest	17.2			16
	Restructuring and other reorganization-related	7.2			46.7
	Other	96.4			118.8
	Total accrued liabilities	$	638.8		$	718.4
Schedule of Other Nonoperating Income (Expense)	'
	Results of operations for the three and nine months ended September 30, 2014 and 2013, include certain items that are not directly associated with our revenue-producing operations.
		Three months ended						Nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
	Loss on early extinguishment of debt	$	0		$	(45.2	)	$	(10.4	)	$	(45.2	)
	Gains (losses) on sales of businesses and investments	0.1			$	(0.8	)	1.2			1.9
	Vendor discounts and credit adjustments	0.3			0.1			2			0.6
	Other (expense) income, net	(1.0		)	(0.7		)	(2.9		)	2.7
	Total other expense, net	$	(0.6	)	$	(46.6	)	$	(10.1	)	$	(40.0	)
Share Repurchase Program	'
	The following table presents our share repurchase activity under our 2013 and 2014 Share Repurchase Programs for the nine months ended September 30, 2014 and 2013.
		Nine months ended
		September 30,
		2014			2013
	Number of shares repurchased	8.3			19.9
	Aggregate cost, including fees	$	148.1		$	280.8
	Average price per share, including fees	$	17.91		$	14.12

Incentive_Compensation_Plans_T

Incentive Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]	'
Stock-based Compensation Awards	'
	We issued the following stock-based awards under the 2009 PIP and 2014 PIP during the nine months ended September 30, 2014.
		Awards	Weighted-average
			grant-date fair value
			(per award)
	Stock-settled awards	1.2	$	17.73
	Performance-based awards	3.5	$	16.56
	Total stock-based compensation awards	4.7

Restructuring_and_Other_Reorga1

Restructuring and Other Reorganization-Related Costs (Tables)	9 Months Ended
	Sep. 30, 2014
Restructuring and Other Reorganization-Related Costs [Abstract]	'
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]	'
	A summary of the 2013 Plan restructuring liability activity is listed below.
		31-Dec-13		Net Restructuring (Reversals) Charges			Cash Payments			Foreign Currency Translation Adjustments			30-Sep-14
	Severance and termination costs	$	46.5	$	(0.3	)	$	(39.5	)	$	(0.3	)	$	6.4
	Lease termination costs	3.9		0.1			(1.2		)	(0.1		)	2.7
	Other exit costs	0.5		0			(0.5		)	0			0
	Total	$	50.9	$	(0.2	)	$	(41.2	)	$	(0.4	)	$	9.1

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss, Net of Tax (Tables)	9 Months Ended
	Sep. 30, 2014
Reclassification of Accumulated Other Comprehensive Income [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	The following tables present 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	(88.4		)	0.4			(0.6		)	(0.6		)	(89.2		)
	Amount reclassified from accumulated other comprehensive loss, net of tax	(0.9		)	(0.3		)	1.1			5.3			5.2
	Balance as of September 30, 2014	$	(333.0	)	$	0.5		$	(11.2	)	$	(151.5	)	$	(495.2	)
		Foreign Currency Translation Adjustments			Available-for-Sale Securities			Derivative Instruments			Defined Benefit Pension and Other Postretirement Plans			Total
	Balance as of December 31, 2012	$	(130.1	)	$	0.8		$	(12.7	)	$	(146.0	)	$	(288.0	)
	Other comprehensive (loss) income before reclassifications	(86.1		)	0.7			0			(0.9		)	(86.3		)
	Amount reclassified from accumulated other comprehensive loss, net of tax	0			(1.2		)	0.8			5.4			5
	Balance as of September 30, 2013	$	(216.2	)	$	0.3		$	(11.9	)	$	(141.5	)	$	(369.3	)
Disclosure of Reclassification Amount	'
	Amounts reclassified from accumulated other comprehensive loss, net of tax for the three and nine months ended September 30, 2014 and 2013 are as follows:
		Three months ended						Nine months ended						Affected Line Item in the Consolidated Statements of Operations
		September 30,						September 30,
		2014			2013			2014			2013
	Foreign currency translation adjustments	$	0		$	0		$	(0.9	)	$	0		Other expense, net
	Gains on available-for-sale securities	0			0			0			(1.4		)	Other expense, net
	Losses on derivative instruments	0.5			0.4			1.4			1.3			Interest expense
	Amortization of defined benefit pension and postretirement plans items 1	2.6			2.7			7.6			8.2
	Tax effect	(1.5		)	(0.9		)	(2.9		)	(3.1		)	Provision for income taxes
	Total amount reclassified from accumulated other comprehensive loss, net of tax	$	1.6		$	2.2		$	5.2		$	5
	1	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 10 for further information.

Employee_Benefits_Tables

Employee Benefits (Tables)	9 Months Ended
	Sep. 30, 2014
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Schedule of Net Periodic Costs	'
	The components of net periodic cost 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
	Three months ended September 30,	2014			2013			2014			2013			2014			2013
	Service cost	$	0		$	0		$	3		$	2.6		$	0		$	0.1
	Interest cost	1.5			1.4			6			5.3			0.4			0.4
	Expected return on plan assets	(1.8		)	(1.9		)	(6.4		)	(4.7		)	0			0
	Settlements and curtailments	0			0			0.1			0			0			0
	Amortization of:
	Prior service cost (credit)	0			0			0			0.1			0			(0.1		)
	Unrecognized actuarial losses	1.7			2			0.9			0.7			0			0
	Net periodic cost	$	1.4		$	1.5		$	3.6		$	4		$	0.4		$	0.4
		Domestic Pension Plan						Foreign Pension Plans						Domestic
														Postretirement Benefit Plan
	Nine months ended September 30,	2014			2013			2014			2013			2014			2013
	Service cost	$	0		$	0		$	7.9		$	7.7		$	0		$	0.1
	Interest cost	4.6			4.1			17.8			15.9			1.3			1.2
	Expected return on plan assets	(5.5		)	(5.8		)	(18.8		)	(14.3		)	0			0
	Settlements and curtailments	0			0			0.1			0			0			0
	Amortization of:
	Prior service cost (credit)	0			0			0.1			0.2			(0.1		)	(0.1		)
	Unrecognized actuarial losses	5			6			2.6			2.1			0			0
	Net periodic cost	$	4.1		$	4.3		$	9.7		$	11.6		$	1.2		$	1.2

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Schedule of Segment Reporting Information, by Segment	'
	Summarized financial information concerning our reportable segments is shown in the following table.
		Three months ended						Nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
	Revenue:
	IAN	$	1,464.60		$	1,370.90		$	4,276.30		$	4,047.70
	CMG	376.5			329.5			1,053.70			951.9
	Total	$	1,841.10		$	1,700.40		$	5,330.00		$	4,999.60
	Segment operating income (loss):
	IAN	$	165.5		$	119.9		$	361		$	266.5
	CMG	47			39.7			105.8			88.3
	Corporate and other	(41.2		)	(18.1		)	(111.4		)	(80.9		)
	Total	171.3			141.5			355.4			273.9
	Interest expense	(20.7		)	(23.7		)	(63.5		)	(98.0		)
	Interest income	7.5			5.8			20.3			18
	Other expense, net	(0.6		)	(46.6		)	(10.1		)	(40.0		)
	Income before income taxes	$	157.5		$	77		$	302.1		$	153.9
	Depreciation and amortization of fixed assets and intangible assets:
	IAN	$	31		$	32.9		$	92.7		$	95.4
	CMG	4.9			3.9			13.7			11.6
	Corporate and other	5.1			3.7			15.3			10.9
	Total	$	41		$	40.5		$	121.7		$	117.9
	Capital expenditures:
	IAN	$	20.9		$	24.5		$	52		$	48
	CMG	2.6			2.4			8.2			6.5
	Corporate and other	12.2			17.9			34.2			37.1
	Total	$	35.7		$	44.8		$	94.4		$	91.6
		September 30,			December 31,
		2014			2013
	Total assets:
	IAN	$	10,689.40		$	11,425.10
	CMG	1,311.50			1,203.80
	Corporate and other	(222.5		)	276.1
	Total	$	11,778.40		$	12,905.00

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following tables present information about our financial instruments measured at fair value on a recurring basis as of September 30, 2014, and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		September 30, 2014												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	470.5		$	0		$	0		$	470.5		Cash and cash equivalents
	Short-term marketable securities	6.4			0			0			6.4			Marketable securities
	Long-term investments	0.5			0			0			0.5			Other non-current assets
	Total	$	477.4		$	0		$	0		$	477.4
	As a percentage of total assets	4.1		%	0		%	0		%	4.1		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	28.8		$	28.8
		December 31, 2013												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	761.2		$	0		$	0		$	761.2		Cash and cash equivalents
	Short-term marketable securities	5.3			0			0			5.3			Marketable securities
	Long-term investments	1.6			0			0			1.6			Other non-current assets
	Total	$	768.1		$	0		$	0		$	768.1
	As a percentage of total assets	6		%	0		%	0		%	6		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	27		$	27
	1	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.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	'
	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 for the three and nine months ended September 30, 2014.
		Three months ended						Nine months ended
		September 30,						September 30,
	Liabilities	2014			2013			2014			2013
	Mandatorily redeemable noncontrolling interests -	$	28.7		$	25.7		$	27		$	25.3
	Balance at beginning of period
	Level 3 additions	0			0			2.5			1
	Level 3 reductions	0			0			(0.6		)	(0.9		)
	Realized losses/(gains) included in net income	0.1			0.3			(0.1		)	0.6
	Mandatorily redeemable noncontrolling interests -	$	28.8		$	26		$	28.8		$	26
	Balance at end of period
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis	'
	The following table presents information about our financial instruments that are not measured at fair value on a recurring basis as of September 30, 2014, and December 31, 2013, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		30-Sep-14												December 31, 2013
		Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Total long-term debt	$	0		$	1,558.40		$	86.6		$	1,645.00		$	0	$	1,367.50	$	87.8	$	1,455.30

Longterm_Debt_Details

Long-term Debt (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Debt Instrument [Line Items]	'		'	'		'	'
(Gain) loss related to early extinguishment of debt	$0		($45.20)	($10.40)		($45.20)	'
Discount	'		'	350.1		601.2	'
Long-term Debt	1,629		'	1,629		'	1,483.40
Less: current portion	2.2	[1]	'	2.2	[1]	'	353.6	[1]
Long-term Debt, Excluding Current Maturities	1,626.80		'	1,626.80		'	1,129.80
Proceeds from Issuance of Long-term Debt	'		'	499.1		0	'
6.25% Notes	'		'	'		'	'
Debt Instrument [Line Items]	'		'	'		'	'
Debt Instrument, Interest Rate, Effective Percentage	6.29%		'	6.29%		'	'
Debt Instrument, Interest Rate, Stated Percentage	6.25%		'	6.25%		'	'
Early Repayment of Senior Debt	'		'	371.2		'	'
(Gain) loss related to early extinguishment of debt	'		'	-10.4		'	'
Interest Paid, Net	'		'	10.3		'	'
Debt Instrument, Face Amount	350		'	350		'	'
Debt Instrument, Maturity Date	'		'	15-Nov-14		'	'
Debt Instrument, Unamortized Discount	0		'	0		'	'
Long-term Debt, Gross	0		'	0		'	351.3
Long-term Debt, Fair Value	0	[2]	'	0	[2]	'	365.6	[2]
2.25% Notes	'		'	'		'	'
Debt Instrument [Line Items]	'		'	'		'	'
Debt Instrument, Interest Rate, Effective Percentage	2.30%		'	2.30%		'	'
Debt Instrument, Interest Rate, Stated Percentage	2.25%		'	2.25%		'	'
Debt Instrument, Maturity Date	'		'	15-Nov-17		'	'
Debt Instrument, Unamortized Discount	0.5		'	0.5		'	'
Long-term Debt, Gross	299.5		'	299.5		'	299.4
Long-term Debt, Fair Value	300.8	[2]	'	300.8	[2]	'	293	[2]
4.00% Notes	'		'	'		'	'
Debt Instrument [Line Items]	'		'	'		'	'
Debt Instrument, Interest Rate, Effective Percentage	4.13%		'	4.13%		'	'
Debt Instrument, Interest Rate, Stated Percentage	4.00%		'	4.00%		'	'
Debt Instrument, Maturity Date	'		'	15-Mar-22		'	'
Debt Instrument, Unamortized Discount	2.3		'	2.3		'	'
Long-term Debt, Gross	247.7		'	247.7		'	247.4
Long-term Debt, Fair Value	254.7	[2]	'	254.7	[2]	'	241.6	[2]
3.75% Notes	'		'	'		'	'
Debt Instrument [Line Items]	'		'	'		'	'
Debt Instrument, Interest Rate, Effective Percentage	4.32%		'	4.32%		'	'
Debt Instrument, Interest Rate, Stated Percentage	3.75%		'	3.75%		'	'
Debt Instrument, Maturity Date	'		'	15-Feb-23		'	'
Debt Instrument, Unamortized Discount	1.3		'	1.3		'	'
Long-term Debt, Gross	498.7		'	498.7		'	498.6
Long-term Debt, Fair Value	496.2	[2]	'	496.2	[2]	'	467.3	[2]
4.20% Notes	'		'	'		'	'
Debt Instrument [Line Items]	'		'	'		'	'
Debt Instrument, Interest Rate, Effective Percentage	4.24%		'	4.24%		'	'
Debt Instrument, Interest Rate, Stated Percentage	4.20%		'	4.20%		'	'
Discount	'		'	0.9		'	'
Debt Instrument, Face Amount	500		'	500		'	'
Debt Instrument, Maturity Date	'		'	15-Apr-24		'	'
Debt Instrument, Unamortized Discount	0.9		'	0.9		'	'
Fees and Commissions	'		'	4.4		'	'
Long-term Debt, Gross	499.1		'	499.1		'	0
Long-term Debt, Fair Value	506.7	[2]	'	506.7	[2]	'	0	[2]
Proceeds from Issuance of Long-term Debt	'		'	494.7		'	'
Debt Instrument, Frequency of Periodic Payment	'		'	'semi-annually		'	'
Other notes payable and capitalized leases	'		'	'		'	'
Debt Instrument [Line Items]	'		'	'		'	'
Long-term Debt, Gross	84		'	84		'	86.7
Long-term Debt, Fair Value	$86.60	[2]	'	$86.60	[2]	'	$87.80	[2]
[1]	We included our 6.25% Senior Unsecured Notes due 2014 (the "6.25% Notes") in the current portion of long-term debt on our December 31, 2013 Consolidated Balance Sheet because the 6.25% Notes were scheduled to mature on November 15, 2014. We redeemed the 6.25% Notes prior to their scheduled maturity during the second quarter of 2014.
[2]	See Note 12 for information on the fair value measurement of our long-term debt.

Credit_Facilities_Details

Credit Facilities (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Debt and Credit Arrangements [Abstract]	'
Line of Credit Facility, Expiration Date	12-Dec-18
Line of Credit Facility, Maximum Borrowing Capacity	$1,000
Line of Credit Facility, Increase (Decrease), Net	250
Line of Credit Facility, Amount Outstanding	$200
Line of Credit Facility, Covenant Compliance	'September 30, 2014

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income available to IPG common stockholders - basic and diluted	$89.70	$45.40	$168.20	$66.10
Weighted Average Number of Shares Outstanding, Basic	419.2	419.7	421	419.7
Restricted stock, stock options and other equity awards, Effect of dilutive securities, Incremental common shares	7.2	6.4	6.2	5.1
Weighted Average Number of Shares Outstanding, Diluted	426.4	426.1	427.2	424.8
Earnings per share available to IPG common stockholders - basic	$0.21	$0.11	$0.40	$0.16
Earnings per share available to IPG common stockholders - diluted	$0.21	$0.11	$0.39	$0.16

Antidilutive_Shares_Details

Antidilutive Shares (Details)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share	'		'		'		'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0		17.3		0		21.7
Antidilutive Stock Options Excluded Exercise Price Greater Than Average Market Pricengs Per Share, Amount	0	[1]	0	[1]	0	[1]	0.2	[1]
4.75% Notes	'		'		'		'
Antidilutive Securities Excluded from Computation of Earnings Per Share	'		'		'		'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	[2]	0	[2]	0	[2]	4.4	[2]
Preferred Stock Outstanding	'		'		'		'
Antidilutive Securities Excluded from Computation of Earnings Per Share	'		'		'		'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	[3]	17.3	[3]	0	[3]	17.3	[3]
[1]	These options are 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.
[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, the potentially dilutive shares are pro-rated based on the period they were outstanding but were antidilutive.
[3]	We converted all of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock into common stock in October 2013.

Acquisitions_Acquisitions_Narr

Acquisitions Acquisitions Narrative (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition	'	'
Number of Businesses Acquired	6	8
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$137	$67
IAN	'	'
Business Acquisition	'	'
Number of Businesses Acquired	4	7
CMG	'	'
Business Acquisition	'	'
Number of Businesses Acquired	2	1

Cash_Paid_for_Acquisitions_Det

Cash Paid for Acquisitions (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Business Combinations [Abstract]	'		'
Cost of investment: current year acquisitions	$87.20		$51.90
Cost of investment: prior-year acquisitions	13.3		28.5
Less: net cash acquired	-24.9		-4.7
Total cost of investment	75.6		75.7
Operating expense	1.8	[1]	1.6	[1]
Total cash paid for acquisitions	77.4	[2]	77.3	[2]
Payments to Acquire Businesses, Net of Cash Acquired	62.9		48.2
Acquisition-related payments	$12.70		$27.50
[1]	Represents cash payments made that were either in excess of the contractual value or contingent upon the future employment of the former owners of the acquired companies.
[2]	Of the total cash paid, $12.7 and $27.5 for the nine months ended September 30, 2014, and 2013, respectively, are classified under the financing section of the unaudited Consolidated Statements of Cash Flows within acquisition-related payments. These amounts relate to increases in our ownership interests in our consolidated subsidiaries, as well as deferred payments for acquisitions that closed on or after January 1, 2009. Of the total cash paid, $62.9 and $48.2 for the nine months ended September 30, 2014, and 2013, respectively, are classified under the investing section of the unaudited Consolidated Statements of Cash Flows within acquisitions, including deferred payments, net of cash acquired. These amounts relate to initial payments for new transactions and deferred payments for acquisitions that closed prior to January 1, 2009.

Redeemable_Noncontrolling_Inte

Redeemable Noncontrolling Interests (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Redeemable Noncontrolling Interest, Equity, Fair Value [Abstract]	'		'
Balance at beginning of period	$249.10		$227.20
Change in related noncontrolling interests balance	-6.7		-4.9
Changes in redemption value of redeemable noncontrolling interests [Abstract]	'		'
Additions	22		12.5
Redemptions and other	-4.5		-2.1
Redemption value adjustments	-4.6	[1]	-3.1	[1]
Balance at end of period	$255.30		$229.60
[1]	Redeemable noncontrolling interests are reported at their estimated redemption value in each reporting period, but not less than their initial fair value. Any adjustment to the redemption value impacts retained earnings or additional paid-in capital, except adjustments as a result of currency translation.

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Accrued Liabilities [Abstract]	'	'
Salaries, benefits and related expenses	$410.70	$467.20
Office and related expenses	50.3	56.9
Acquisition obligations	57	12.8
Interest	17.2	16
Restructuring and other reorganization-related	7.2	46.7
Other	96.4	118.8
Total accrued liabilities	$638.80	$718.40

Other_Expense_Income_Net_Detai

Other (Expense) Income, Net (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Nonoperating Income (Expense) [Abstract]	'	'	'	'
Total other expense, net	$0.60	$46.60	$10.10	$40
Loss on early extinguishment of debt	0	-45.2	-10.4	-45.2
Gains (losses) on sales of businesses and investments	0.1	-0.8	1.2	1.9
Vendor discounts and credit adjustments	0.3	0.1	2	0.6
Other (expense) income, net	($1)	($0.70)	($2.90)	$2.70

Supplementary_Data_Loss_on_Ear

Supplementary Data Loss on Early Extinguishment of Debt (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Loss on Extinguishment of Debt	$0	$45.20	$10.40	$45.20
6.25% Notes	'	'	'	'
Loss on Extinguishment of Debt	'	'	10.4	'
10.0% Note	'	'	'	'
Loss on Extinguishment of Debt	'	'	'	$45.20

Share_Repurchase_Program_Detai

Share Repurchase Program (Details) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Share Repurchase Program	'	'
Number of shares repurchased	8.3	19.9
Aggregate cost, including fees	$148.10	$280.80
Average price per share, including fees	$17.91	$14.12
Share repurchase program, remaining authorized repurchase amount	270.6	'
2013 Share Repurchase Program	'	'
Share Repurchase Program	'	'
Share repurchase program, authorized amount	300	'
Share repurchase program, increased authorized amount	500	'
2014 Share Repurchase Program	'	'
Share Repurchase Program	'	'
Share repurchase program, authorized amount	$300	'

Income_Taxes_Effective_Income_

Income Taxes Effective Income Tax Rate (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'	'
Effective income tax rate	41.30%	42.60%
One hundred percent valuation allowance	'	100.00%

Income_Taxes_Change_in_Unrecog

Income Taxes Change in Unrecognized Tax Benefits (Details) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Income Tax Disclosure [Abstract]	'
Estimated unrecognized tax benefit decrease, lower bound	$30
Estimated unrecognized tax benefit decrease, upper bound	$40

Tax_Years_Open_to_Examinations

Tax Years Open to Examinations (Details) (Minimum)	9 Months Ended
	Sep. 30, 2014
Domestic Tax Authority	'
Income Tax Contingency	'
Open Tax Year	'2009
State and Local Jurisdiction	'
Income Tax Contingency	'
Open Tax Year	'2004
Foreign Tax Authority	'
Income Tax Contingency	'
Open Tax Year	'2006

Incentive_Compensation_Plans_P

Incentive Compensation Plans Plan Information (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Incentive Compensation Plan Initiation Year	'2014
Number of shares initially available for grants	28.8
Maximum shares participants are eligible to receive	2
Performance Vesting Condition	'range from 0% to 300% of the target amount
Maximum Cash Award Value Per Employee	$10
Cash awards vesting period	'3 years

Incentive_Compensation_Plans_S

Incentive Compensation Plans Stock-based Compensation Awards (Details) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014
Incentive Compensation Plans	'
Incentive Compensation Plan Initiation Year	'2014
Number of shares initially available for grants	28.8
Total target value of cash awards granted	$1.50
Restricted Cash Plan cash awards granted during the period target value	0.8
Cash awards vesting period	'3 years
Stock settled awards	'
Incentive Compensation Plans	'
Granted awards	1.2
Weighted Average Grant Date Fair Value	$17.73
Performance based awards	'
Incentive Compensation Plans	'
Granted awards	3.5
Weighted Average Grant Date Fair Value	$16.56
Stock Compensation Plan	'
Incentive Compensation Plans	'
Granted awards	4.7
2009 PIP	'
Incentive Compensation Plans	'
Incentive Compensation Plan Initiation Year	'2009
Total target value of cash awards granted	31.4
Restricted Cash Plan cash awards granted during the period target value	$4.80

Restructuring_and_Other_Reorga2

Restructuring and Other Reorganization-Related Costs 2013 Plan (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
2013 Restructuring Plan	'
Restructuring Cost and Reserve	'
Beginning liability balance	$50.90
Net Restructuring (Reversals) Charges	-0.2
Cash payments	-41.2
Restructuring Reserve, Translation and Other Adjustment	-0.4
Ending liability balance	9.1
Prior Year Restructuring Plans [Domain]	'
Restructuring Cost and Reserve	'
Net Restructuring (Reversals) Charges	0.3
Ending liability balance	1.2
Severance and termination costs | 2013 Restructuring Plan	'
Restructuring Cost and Reserve	'
Beginning liability balance	46.5
Net Restructuring (Reversals) Charges	-0.3
Cash payments	-39.5
Restructuring Reserve, Translation and Other Adjustment	-0.3
Ending liability balance	6.4
Lease termination costs | 2013 Restructuring Plan	'
Restructuring Cost and Reserve	'
Beginning liability balance	3.9
Net Restructuring (Reversals) Charges	0.1
Cash payments	-1.2
Restructuring Reserve, Translation and Other Adjustment	-0.1
Ending liability balance	2.7
Other exit costs | 2013 Restructuring Plan	'
Restructuring Cost and Reserve	'
Beginning liability balance	0.5
Net Restructuring (Reversals) Charges	0
Cash payments	-0.5
Restructuring Reserve, Translation and Other Adjustment	0
Ending liability balance	0
CMG | 2013 Restructuring Plan	'
Restructuring Cost and Reserve	'
Net Restructuring (Reversals) Charges	($0.20)

Restructuring_and_Other_Reorga3

Restructuring and Other Reorganization-Related Costs Prior Year Plans (Details) (Prior Year Restructuring Plans [Domain], USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Prior Year Restructuring Plans [Domain]	'
Restructuring Reserve	$1.20
Net Restructuring (Reversals) Charges	$0.30

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss, Net of Tax (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Foreign Currency Translation Adjustment:	'	'	'	'
Balance at beginning of period	'	'	($243.70)	($130.10)
Other comprehensive (loss) income before reclassifications	'	'	-88.4	-86.1
Amount reclassified from accumulated other comprehensive loss, net of tax	'	'	-0.9	0
Balance at end of period	-333	-216.2	-333	-216.2
Available-for-sale Securities:	'	'	'	'
Balance at beginning of period	'	'	0.4	0.8
Other comprehensive (loss) income before reclassifications	'	'	0.4	0.7
Amount reclassified from accumulated other comprehensive loss, net of tax	'	'	-0.3	-1.2
Balance at end of period	0.5	0.3	0.5	0.3
Derivative instruments:	'	'	'	'
Balance at beginning of period	'	'	-11.7	-12.7
Other comprehensive (loss) income before reclassifications	0	0	-0.6	0
Amount reclassified from accumulated other comprehensive loss, net of tax	'	'	1.1	0.8
Balance at end of period	-11.2	-11.9	-11.2	-11.9
Defined benefit pension and other postretirement plans:	'	'	'	'
Balance at beginning of period	'	'	-156.2	-146
Other comprehensive (loss) income before reclassifications	'	'	-0.6	-0.9
Amount reclassified from accumulated other comprehensive loss,net of tax	'	'	5.3	5.4
Balance at end of period	-151.5	-141.5	-151.5	-141.5
Total Changes in Accumulated Other Comprehensive Loss, Net of Tax [Abstract]	'	'	'	'
Balance at beginning of period	'	'	-411.2	-288
Other comprehensive (loss) income before reclassifications	'	'	-89.2	-86.3
Amount reclassified from accumulated other comprehensive loss, net of tax	1.6	2.2	5.2	5
Balance at end of period	($495.20)	($369.30)	($495.20)	($369.30)

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Loss, Net of Tax Reclassification of Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Reclassification of Accumulated Other Comprehensive Income [Abstract]	'		'		'		'
Foreign currency translation adjustments	$0		$0		($0.90)		$0
Gains on available-for-sale securities	0		0		0		-1.4
Losses on derivative instruments	0.5		0.4		1.4		1.3
Amortization of defined benefit pension and postretirement plans items	2.6	[1]	2.7	[1]	7.6	[1]	8.2	[1]
Tax effect	-1.5		-0.9		-2.9		-3.1
Total amount reclassified from accumulated other comprehensive loss, net of tax	$1.60		$2.20		$5.20		$5
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 10 for further information.

Employee_Benefits_Details

Employee Benefits (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Domestic Pension Plan	'	'	'	'
Defined Pension and Postretirement Benefit Plans	'	'	'	'
Service cost	$0	$0	$0	$0
Interest cost	1.5	1.4	4.6	4.1
Expected return on plan assets	-1.8	-1.9	-5.5	-5.8
Settlements and curtailments	0	0	0	0
Amortization of:	'	'	'	'
Prior service cost (credit)	0	0	0	0
Unrecognized actuarial losses	1.7	2	5	6
Net periodic cost	1.4	1.5	4.1	4.3
Pension Plan - Employer Contributions	'	'	2.1	'
Pension Plan - Estimated Employer Contributions Current fiscal year	'	'	1	'
Foreign Pension Plans	'	'	'	'
Defined Pension and Postretirement Benefit Plans	'	'	'	'
Service cost	3	2.6	7.9	7.7
Interest cost	6	5.3	17.8	15.9
Expected return on plan assets	-6.4	-4.7	-18.8	-14.3
Settlements and curtailments	0.1	0	0.1	0
Amortization of:	'	'	'	'
Prior service cost (credit)	0	0.1	0.1	0.2
Unrecognized actuarial losses	0.9	0.7	2.6	2.1
Net periodic cost	3.6	4	9.7	11.6
Pension Plan - Employer Contributions	'	'	17.8	'
Pension Plan - Estimated Employer Contributions Current fiscal year	'	'	7	'
Domestic Postretirement Benefit Plan	'	'	'	'
Defined Pension and Postretirement Benefit Plans	'	'	'	'
Service cost	0	0.1	0	0.1
Interest cost	0.4	0.4	1.3	1.2
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	-0.1	-0.1
Unrecognized actuarial losses	0	0	0	0
Net periodic cost	$0.40	$0.40	$1.20	$1.20

Segment_Information_Operations

Segment Information Operations (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segments:	'	'	'	'	'
Revenue	$1,841.10	$1,700.40	$5,330	$4,999.60	'
Operating Income (Loss)	171.3	141.5	355.4	273.9	'
Interest expense	20.7	23.7	63.5	98	'
Interest income	-7.5	-5.8	-20.3	-18	'
Total other expense, net	0.6	46.6	10.1	40	'
Income before income taxes	157.5	77	302.1	153.9	'
Depreciation and amortization of fixed assets and intangible assets	41	40.5	121.7	117.9	'
Capital expenditures	35.7	44.8	94.4	91.6	'
Assets	11,778.40	'	11,778.40	'	12,905
IAN	'	'	'	'	'
Segments:	'	'	'	'	'
Revenue	1,464.60	1,370.90	4,276.30	4,047.70	'
Operating Income (Loss)	165.5	119.9	361	266.5	'
Depreciation and amortization of fixed assets and intangible assets	31	32.9	92.7	95.4	'
Capital expenditures	20.9	24.5	52	48	'
Assets	10,689.40	'	10,689.40	'	11,425.10
CMG	'	'	'	'	'
Segments:	'	'	'	'	'
Revenue	376.5	329.5	1,053.70	951.9	'
Operating Income (Loss)	47	39.7	105.8	88.3	'
Depreciation and amortization of fixed assets and intangible assets	4.9	3.9	13.7	11.6	'
Capital expenditures	2.6	2.4	8.2	6.5	'
Assets	1,311.50	'	1,311.50	'	1,203.80
Corporate and Other	'	'	'	'	'
Segments:	'	'	'	'	'
Operating Income (Loss)	-41.2	-18.1	-111.4	-80.9	'
Depreciation and amortization of fixed assets and intangible assets	5.1	3.7	15.3	10.9	'
Capital expenditures	12.2	17.9	34.2	37.1	'
Assets	($222.50)	'	($222.50)	'	$276.10

Segment_Information_Balance_Sh

Segment Information Balance Sheet (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Segments:	'	'
Assets	$11,778.40	$12,905
IAN	'	'
Segments:	'	'
Assets	10,689.40	11,425.10
CMG	'	'
Segments:	'	'
Assets	1,311.50	1,203.80
Corporate and Other	'	'
Segments:	'	'
Assets	($222.50)	$276.10

Fair_Value_on_a_Recurring_Basi

Fair Value on a Recurring Basis (Details) (USD $)	Sep. 30, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Level 1	'		'
Fair value assets and liabilities measured on recurring and nonrecurring basis	'		'
Cash equivalents	$470.50		$761.20
Short-term marketable securities	6.4		5.3
Long-term investments	0.5		1.6
Fair Value of Total Assets, Recurring	477.4		768.1
Fair value of assets measured on a recurring basis, percentage of total assets	4.10%		6.00%
Mandatorily redeemable noncontrolling interests	0	[1]	0	[1]
Level 2	'		'
Fair value assets and liabilities measured on recurring and nonrecurring 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%		0.00%
Mandatorily redeemable noncontrolling interests	0	[1]	0	[1]
Level 3	'		'
Fair value assets and liabilities measured on recurring and nonrecurring 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%		0.00%
Mandatorily redeemable noncontrolling interests	28.8	[1]	27	[1]
Fair Value, Total	'		'
Fair value assets and liabilities measured on recurring and nonrecurring basis	'		'
Cash equivalents	470.5		761.2
Short-term marketable securities	6.4		5.3
Long-term investments	0.5		1.6
Fair Value of Total Assets, Recurring	477.4		768.1
Fair value of assets measured on a recurring basis, percentage of total assets	4.10%		6.00%
Mandatorily redeemable noncontrolling interests	$28.80	[1]	$27	[1]
[1]	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.

Fair_Value_Unobservable_Inputs

Fair Value Unobservable Inputs (Details) (Mandatorily redeemable noncontrolling interests [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Mandatorily redeemable noncontrolling interests [Member]	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	'	'	'	'
Balance at beginning of period	$28.70	$25.70	$27	$25.30
Level 3 additions	0	0	2.5	1
Level 3 reductions	0	0	-0.6	-0.9
Realized losses/(gains) included in net income	0.1	0.3	-0.1	0.6
Balance at end of period	$28.80	$26	$28.80	$26

Fair_Value_Measurements_Fair_V

Fair Value Measurements Fair Value on a Nonrecurring Basis (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Level 1	'	'
Fair value assets and liabilities measured on recurring and nonrecurring basis	'	'
Total long-term debt	$0	$0
Level 2	'	'
Fair value assets and liabilities measured on recurring and nonrecurring basis	'	'
Total long-term debt	1,558.40	1,367.50
Level 3	'	'
Fair value assets and liabilities measured on recurring and nonrecurring basis	'	'
Total long-term debt	86.6	87.8
Fair Value, Total	'	'
Fair value assets and liabilities measured on recurring and nonrecurring basis	'	'
Total long-term debt	$1,645	$1,455.30

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
Lease guarantees	$564	$588.10
Credit facility guarantees	$324.80	$279.60