The Interpublic Group of Companies, Inc. (IPG) 10-Q 24 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 15, 2013
Document and Entity Information [Abstract]
Amendment Flag	FALSE
Entity Registrant Name	INTERPUBLIC GROUP OF COMPANIES, INC.
Entity Central Index Key	51644
Entity Common Stock, Shares Outstanding		416,241,739
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3

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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
REVENUE	$1,700.40	$1,670.40	$4,999.60	$4,892.90
OPERATING EXPENSES:
Salaries and related expenses	1,093.60	1,064.30	3,345.90	3,258.10
Office and general expenses	465.3	474.7	1,379.80	1,366.40
Total operating expenses	1,558.90	1,539	4,725.70	4,624.50
OPERATING INCOME	141.5	131.4	273.9	268.4
EXPENSES AND OTHER INCOME:
Interest expense	-23.7	-31.6	-98	-96.9
Interest income	5.8	6.7	18	21.4
Other (expense) income, net	-46.6	1.7	-40	5.1
Total (expenses) and other income	-64.5	-23.2	-120	-70.4
Income before income taxes	77	108.2	153.9	198
Provision for income taxes	28.4	41.9	78	72.8
Income of consolidated companies	48.6	66.3	75.9	125.2
Equity in net income of unconsolidated affiliates	0.6	1.4	0.9	2.3
NET INCOME	49.2	67.7	76.8	127.5
Net (income) loss attributable to noncontrolling interests	-0.9	3.9	-2	3
NET INCOME ATTRIBUTABLE TO IPG	48.3	71.6	74.8	130.5
Dividends on preferred stock	-2.9	-2.9	-8.7	-8.7
NET INCOME AVAILABLE TO IPG COMMON STOCKHOLDERS	$45.40	$68.70	$66.10	$121.80
Earnings per share available to IPG common stockholders, Basic	$0.11	$0.16	$0.16	$0.28
Earnings per share available to IPG common stockholders, Diluted	$0.11	$0.15	$0.16	$0.27
Weighted-average number of common shares outstanding, Basic	419.7	431.3	419.7	435.5
Weighted-average number of common shares outstanding, Diluted	426.1	456.1	424.8	469.7
Dividends declared per common share	$0.08	$0.06	$0.23	$0.18

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
NET INCOME	$49.20		$67.70	$76.80		$127.50
OTHER COMPREHENSIVE INCOME (LOSS)
Foreign currency translation adjustments	24		37.3	-89.3		16.1
Available-for-sale securities:
Changes in market value of available-for sale securities	-0.1		-40.8	0.7		94.7
Less: recognition of previously unrealized (gains) losses included in net income	0		0	-1.4		0.6
Available-for-sale securities, Income tax effect	0		15.8	0.2		-34.8
Available-for-sale securities, net of tax	-0.1		-25	-0.5		60.5
Derivative instruments:
Changes in fair value of derivative instruments	0		-3.6	0		-22.2
Less: recognition of previously unrealized losses in net income	0.4		0	1.3		0
Derivative instruments, Income tax effect	-0.1		1.5	-0.5		9.2
Derivative instruments, net of tax	0.3		-2.1	0.8		-13
Defined benefit pension and other postretirement plans:
Net actuarial gains for the period	0		0	0		1
Less: amortization of unrecognized losses, transition obligation and prior service cost included in net income	2.7	[1]	2	8.2	[1]	5.7
Other	-0.2		-0.3	-0.9		-0.4
Defined benefit pension and other postretirement plans, Income tax effect	-0.8		-0.6	-2.8		-2.3
Defined benefit pension and other postretirement plans, net of tax	1.7		1.1	4.5		4
Other comprehensive income (loss), net of tax	25.9		11.3	-84.5		67.6
Total Comprehensive Income (Loss)	75.1		79	-7.7		195.1
Less: comprehensive income (loss) attributable to noncontrolling interests	0.7		-3.3	-1.2		-3.5
Comprehensive Income (Loss) Attributable to IPG	$74.40		$82.30	($6.50)		$198.60
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 9 for further information.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$65.70	$59
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$1,160.20	$1,134.90

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
ASSETS:
Cash and cash equivalents	$999.30		$2,574.80
Marketable securities	5.2		16
Accounts receivable, net of allowance of $65.7 and $59.0, respectively	3,830.20		4,496.60
Expenditures billable to clients	1,551		1,318.80
Other current assets	377.1		332.1
Total current assets	6,762.80		8,738.30
Furniture, equipment and leasehold improvements, net of accumulated depreciation of $1,160.2 and $1,134.9, respectively	490.5		504.8
Deferred income taxes	171.3		160.5
Goodwill	3,609.30		3,580.60
Other non-current assets	498.1		509.7
TOTAL ASSETS	11,532		13,493.90
LIABILITIES:
Accounts payable	5,705.60		6,584.80
Accrued liabilities	553.3		728.2
Short-term borrowings	186.3		172.1
Current portion of long-term debt	2.2	[1]	216.6	[1]
Total current liabilities	6,447.40		7,701.70
Long-term debt	1,481		2,060.80
Deferred compensation	483.3		489
Other non-current liabilities	557.2		558.6
TOTAL LIABILITIES	8,968.90		10,810.10
Redeemable noncontrolling interests (see Note 5)	229.6		227.2
STOCKHOLDERS' EQUITY:
Preferred stock	221.5		221.5
Common stock	51.2		48.8
Additional paid-in capital	2,754.10		2,465.40
Retained earnings	710.4		738.3
Accumulated other comprehensive loss, net of tax	-369.3		-288
Stockholders Equity Subtotal Before Treasury Stock	3,367.90		3,186
Less: Treasury stock	-1,065.30		-765.4
Total IPG stockholders' equity	2,302.60		2,420.60
Noncontrolling interests	30.9		36
TOTAL STOCKHOLDERS' EQUITY	2,333.50		2,456.60
TOTAL LIABILITIES AND EQUITY	$11,532		$13,493.90
[1]	We included our 4.75% Convertible Senior Notes due 2023 (the b4.75% Notesb) in the current portion of long-term debt on our DecemberB 31, 2012 Consolidated Balance Sheet because holders of the 4.75% Notes had an option to require us to repurchase their Notes for cash, stock or a combination, at our election, at par on MarchB 15, 2013. The 4.75% Notes were retired in the first quarter of 2013.

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$76.80	$127.50
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization of fixed assets and intangible assets	117.9	108.8
Provision for uncollectible receivables	11.4	11.8
Amortization of restricted stock and other non-cash compensation	32.9	37.7
Net amortization of bond discounts and deferred financing costs	5.4	0.3
Non-cash loss on early extinguishment of debt	15.2	0
Deferred income tax provision (benefit)	28.5	-31.5
Other	-7.4	10
Changes in assets and liabilities, net of acquisitions and dispositions, providing (using) cash:
Accounts receivable	586.9	610.2
Expenditures billable to clients	-250.9	-268.4
Other current assets	-38.8	-17.8
Accounts payable	-811.5	-852.7
Accrued liabilities	-152.9	-172
Other non-current assets and liabilities	-43.9	-9.2
Net cash used in operating activities	-430.4	-445.3
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	-91.6	-99.3
Acquisitions, including deferred payments, net of cash acquired	-48.2	-140.6
Net sales (purchases) and maturities of short-term marketable securities	10.8	-0.8
Proceeds from sales of businesses and investments, net of cash sold	3.3	12.1
Other investing activities	-2.4	-0.7
Net cash used in investing activities	-128.1	-229.3
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of long-term debt	-601.2	-401
Proceeds from issuance long-term debt	0	246.8
Repurchase of common stock	-280.8	-201.4
Common stock dividends	-94.1	-78.1
Exercise of stock options	43.6	8.5
Acquisition-related payments	-27.5	-36.1
Net increase in short-term bank borrowings	13.3	45.5
Distributions to noncontrolling interests	-10.4	-12.2
Preferred stock dividends	-8.7	-8.7
Excess tax benefit on share-based compensation	9.2	0
Other financing activities	1	-3
Net cash used in financing activities	-955.6	-439.7
Effect of foreign exchange rate changes on cash and cash equivalents	-61.4	-1.1
Net decrease in cash and cash equivalents	-1,575.50	-1,115.40
Cash and cash equivalents at beginning of period	2,574.80	2,302.70
Cash and cash equivalents at end of period	$999.30	$1,187.30

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Preferred Stock	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
Beginning balance at Dec. 31, 2011	$2,497.30	$221.50	$48.20	$2,427.50	$405.10	($225.70)	($414.90)	$2,461.70	$35.60
Beginning balance, shares at Dec. 31, 2011			491.4
Net income	127.5				130.5			130.5	-3
Other comprehensive income (loss)	67.6					68.1		68.1	-0.5
Reclassifications related to redeemable noncontrolling interests	20.3			12				12	8.3
Noncontrolling interest transactions	-1.3								-1.3
Distributions to noncontrolling interests	-12.2								-12.2
Change in redemption value of redeemable noncontrolling interests	3.1				3.1			3.1
Repurchase of common stock	-201.4						-201.4	-201.4
Common stock dividends	-78.1				-78.1			-78.1
Preferred stock dividends	-8.7				-8.7			-8.7
Stock-based compensation, shares			1.8
Stock-based compensation	26.5		0.7	25.8				26.5
Exercise of stock options, shares			0.9
Exercise of stock options	8.6		0.1	8.5				8.6
Shares withheld for taxes, shares			-2.1
Shares withheld for taxes	-23.5		-0.2	-23.3				-23.5
Other	0.8			-2	-1			-3	3.8
Ending balance at Sep. 30, 2012	2,426.50	221.5	48.8	2,448.50	450.9	-157.6	-616.3	2,395.80	30.7
Ending balance, shares at Sep. 30, 2012			492
Beginning balance at Dec. 31, 2012	2,456.60	221.5	48.8	2,465.40	738.3	-288	-765.4	2,420.60	36
Beginning balance, shares at Dec. 31, 2012			492
Net income	76.8				74.8			74.8	2
Other comprehensive income (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	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
Ending balance at Sep. 30, 2013	$2,333.50	$221.50	$51.20	$2,754.10	$710.40	($369.30)	($1,065.30)	$2,302.60	$30.90
Ending balance, shares at Sep. 30, 2013			514.5

Basis_of_Presentation_Notes

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2013
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 2012 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. Certain reclassifications have been made to prior-period financial statements to conform to the current-period presentation.

Debt_and_Credit_Arrangements_N

Debt and Credit Arrangements (Notes)	9 Months Ended
	Sep. 30, 2013
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	2013				2012
			Book		Fair		Book		Fair
			Value		Value 1		Value		Value 1
	6.25% Senior Unsecured Notes due 2014 (less unamortized	6.29%	$	351.6	$	369.4	$	352.8	$	372.6
	discount of $0.1)
	2.25% Senior Notes due 2017 (less unamortized	2.30%	299.4		296.7		299.3		297.8
	discount of $0.6)
	4.00% Senior Notes due 2022 (less unamortized	4.13%	247.3		242		247.1		258.7
	discount of $2.7)
	3.75% Senior Notes due 2023 (less unamortized	4.32%	498.6		469.3		498.5		499.7
	discount of $1.4)
	10.00% Senior Unsecured Notes due 2017		0		0		591.9		660.8
	4.75% Convertible Senior Notes due 2023		0		0		200.5		202.8
	Other notes payable and capitalized leases		86.3		85.8		87.3		90.8
	Total long-term debt		1,483.20				2,277.40
	Less: current portion 2		2.2				216.6
	Long-term debt, excluding current portion		$	1,481.00			$	2,060.80
	1	See Note 11 for information on the fair value measurement of our long-term debt.
	2	We included our 4.75% Convertible Senior Notes due 2023 (the “4.75% Notes”) in the current portion of long-term debt on our December 31, 2012 Consolidated Balance Sheet because holders of the 4.75% Notes had an option to require us to repurchase their Notes for cash, stock or a combination, at our election, at par on March 15, 2013. The 4.75% Notes were retired in the first quarter of 2013.
	Debt Transactions
	10.00% Senior Unsecured Notes due 2017
	In July 2013, we redeemed all $600.0 in aggregate principal amount of the 10.00% Senior Unsecured Notes due 2017 (the "10.00% Notes"). Total cash paid to redeem the 10.00% Notes was $630.0. In connection with the redemption of the 10.00% Notes, we recognized a loss on early extinguishment of debt of $45.2, which included a redemption premium of $30.0, the write-off of the remaining unamortized discount of $7.3 and unamortized debt issuance costs of $7.9. The loss on early extinguishment of debt was recorded in other (expense) income, net within our unaudited Consolidated Statement of Operations.
	4.75% Convertible Senior Notes due 2023
	In March 2013, we retired all $200.0 in aggregate principal amount of our 4.75% Notes. Of the amount retired, $199.997 in aggregate principal amount of the 4.75% Notes was converted, at the election of the holders, into Interpublic common stock at a conversion rate of 84.3402 shares (actual number) per $1,000 (actual number) principal amount, or approximately 16.9 shares.
	Capped Call
	In November 2010, we purchased capped call options to hedge the risk of price appreciation on the shares of our common stock into which our 4.75% Notes were convertible. In March 2013, we exercised our capped call options and elected net share settlement. We received a total of 1.5 settlement shares from the option counterparties as a result of exercising these options.
	Interest Rate Swaps
	We enter into interest rate swaps to manage our exposure to changes in interest rates. In March and April 2012, we entered into forward-starting interest rate swap agreements with an aggregate notional amount of $300.0 to effectively lock in the benchmark rate for a forecasted issuance of debt to occur prior to December 31, 2013. These swaps qualified for hedge accounting as cash flow hedges, and, as such, the effective portion of the losses on the swaps was recorded in other comprehensive income and the ineffective portion of the losses on the swaps was recorded in other (expense) income, net. In November 2012, we terminated these swaps when we issued our 3.75% Senior Notes due 2022 (the "3.75% Notes"). The deferred losses on the swaps, recorded in accumulated other comprehensive loss, are amortized as an increase to interest expense over the term of the 3.75% Notes.
	During the first nine months of 2013, we reclassified $1.3 from accumulated other comprehensive loss into interest expense. Over the next twelve months, we expect to reclassify $1.8 from accumulated other comprehensive loss into interest expense in our unaudited Consolidated Statements of Operations.
	Credit Agreement
	We maintain a committed corporate credit facility to increase our financial flexibility (the "Credit Agreement"). The Credit Agreement is a revolving facility expiring in May 2016, 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 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, 2013.

Convertible_Preferred_Stock_No

Convertible Preferred Stock (Notes)	9 Months Ended
	Sep. 30, 2013
Convertible Preferred Stock [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock
	The conversion rate of our 5 1/4% Series B Cumulative Convertible Perpetual Preferred Stock (the "Series B Preferred Stock")is subject to adjustment upon the occurrence of certain events, including the payment of cash dividends on our common stock. During the third quarter of 2013, the conversion rate per share for our Series B Preferred Stock was adjusted from 77.1251 to 77.8966 as a result of the cumulative effect of the cash dividends declared and paid on our common stock during the second and third quarters of 2013, resulting in a corresponding adjustment of the conversion price from $12.97 to $12.84. See Note 14 for further information regarding subsequent events.

Earnings_Per_Share_Notes

Earnings Per Share (Notes)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]
Earnings Per Share	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,
		2013			2012			2013		2012
	Net income available to IPG common stockholders - basic	$	45.4		$	68.7		$	66.1	$	121.8
	Adjustments: Effect of dilutive securities
	Interest on 4.75% Notes 1	0			1			0		3.1
	Interest on 4.25% Notes 1	0			0			0		0.3
	Net income available to IPG common stockholders - diluted	$	45.4		$	69.7		$	66.1	$	125.2
	Weighted-average number of common shares outstanding - basic	419.7			431.3			419.7		435.5
	Add: Effect of dilutive securities
	Restricted stock, stock options and other equity awards	6.4			8.1			5.1		7.1
	4.75% Notes 1	0			16.7			0		16.7
	4.25% Notes 1	0			0			0		10.4
	Weighted-average number of common shares outstanding - diluted	426.1			456.1			424.8		469.7
	Earnings per share available to IPG common stockholders - basic	$	0.11		$	0.16		$	0.16	$	0.28
	Earnings per share available to IPG common stockholders - diluted	$	0.11		$	0.15		$	0.16	$	0.27
	1	We retired all of our outstanding 4.75% Notes and 4.25% Convertible Senior Notes due 2023 (the “4.25% Notes”) in March 2013 and March 2012, respectively. See Note 2 for further information on our 4.75% Notes. For purposes of calculating diluted earnings per share, the potentially dilutive shares are pro-rated based on the period they were outstanding.
	The following table presents the potential shares excluded from the diluted earnings per share calculation because the effect of including these potential shares would be antidilutive.
		Three months ended					Nine months ended
		September 30,					September 30,
		2013		2012			2013		2012
	4.75% Notes 1	0		0			4.4		0
	Preferred stock outstanding	17.3		16.9			17.3		16.9
	Total	17.3		16.9			21.7		16.9
	Securities excluded from the diluted earnings per share calculation
	because the exercise price was greater than the average market price:
	Stock options 2	0		7.1			0.2		7.1
	1	We retired all of our outstanding 4.75% Notes in March 2013. See Note 2 for further information on our 4.75% Notes. For purposes of calculating diluted earnings per share, the potentially dilutive shares are pro-rated based on the period they were outstanding.
	2	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, 2013
Business Combinations [Abstract]
Business Combination Disclosure	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. In addition, we have entered into agreements that may require us to purchase additional equity interests in certain consolidated and unconsolidated subsidiaries. The amounts at which we record these transactions in our financial statements are based on estimates of the future financial performance of the acquired entity, the timing of the exercise of these rights, changes in foreign currency exchange rates and other factors.
	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 Integrated Agency Networks (“IAN”) operating segment and one was included in the Constituency Management Group ("CMG") operating segment. During the first nine months of 2013, we recorded approximately $67.0 of goodwill and intangible assets related to these acquisitions.
	During the first nine months of 2012, we completed eleven acquisitions, including a healthcare market research and consulting agency and a search marketing agency in the United Kingdom and, in the United States, a digital healthcare-marketing specialist and a designer of in-store shopping experiences. Of our eleven acquisitions, seven were included in the IAN operating segment and four were included in the CMG operating segment. During the first nine months of 2012, we recorded approximately $205.0 of goodwill and intangible assets related to these acquisitions.
	The results of operations of our acquired companies were included in our consolidated results from the closing date of each acquisition. Details of cash paid for current and prior years' acquisitions are listed below.
		Nine months ended
		September 30,
		2013			2012
	Cost of investment: current-year acquisitions	$	51.9		$	154.3
	Cost of investment: prior-year acquisitions	28.5			37
	Less: net cash acquired	(4.7		)	(14.6		)
	Total cost of investment	75.7			176.7
	Operating expense 1	1.6			3.2
	Total cash paid for acquisitions 2	$	77.3		$	179.9
	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 acquired companies.
	2	Of the total cash paid, $27.5 and $36.1 for the nine months ended September 30, 2013, and 2012, 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, $48.2 and $140.6 for the nine months ended September 30, 2013, and 2012, 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,
		2013			2012
	Balance at beginning of period	$	227.2		$	243.4
	Change in related noncontrolling interests balance	(4.9		)	(8.3		)
	Changes in redemption value of redeemable noncontrolling interests:
	Additions	12.5			3
	Redemptions and other	(2.1		)	(14.2		)
	Redemption value adjustments 1	(3.1		)	(3.6		)
	Balance at end of period	$	229.6		$	220.3
	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, 2013
Supplementary Data [Abstract]
Supplementary Data	Supplementary Data
	Accrued Liabilities
	The following table presents the components of accrued liabilities.
		September 30,			December 31,
		2013			2012
	Salaries, benefits and related expenses	$	370.9		$	478.2
	Office and related expenses	52.9			51.6
	Acquisition obligations	9.2			29.5
	Interest	15.9			42.4
	Professional fees	17.6			21.7
	Other	86.8			104.8
	Total accrued liabilities	$	553.3		$	728.2
	Other (Expense) Income, Net
	Results of operations for the three and nine months ended September 30, 2013 and 2012 include certain items that are not directly associated with our revenue-producing operations.
		Three months ended						Nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Loss on early extinguishment of debt	$	(45.2	)	$	0		$	(45.2	)	$	0
	(Losses) gains on sales of businesses and investments	(0.8		)	(3.4		)	1.9			(5.2		)
	Vendor discounts and credit adjustments	0.1			5			0.6			9.9
	Other (expense) income, net	(0.7		)	0.1			2.7			0.4
	Total other (expense) income, net	$	(46.6	)	$	1.7		$	(40.0	)	$	5.1
	Loss on Early Extinguishment of Debt – During the third quarter of 2013, we recorded a charge of $45.2 related to the redemption of our 10.00% Notes. See Note 2 to the unaudited Consolidated Financial Statements for further information.
	Sales of Businesses and Investments – During the first nine months of 2013, we recognized gains from the sale of marketable securities in the Asia Pacific region within our IAN segment and the sale of investments in our Rabbi Trusts, which 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. During the first nine months of 2012, we recognized losses from the sale of businesses within our IAN segment, as well as an adjustment relating to a reserve for a change in estimate in connection with a business disposed of in a prior year.
	Vendor Discounts and Credit Adjustments – We are in the process of settling our liabilities related to vendor discounts and credits established as part of the 2004 Restatement. These adjustments reflect the reversal of certain of these liabilities as a result of differences resulting from settlements with clients or vendors or where the statute of limitations has lapsed.
	Other (Expense) Income, net – During the first nine months of 2013, other (expense) income, 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.
	Accumulated Other Comprehensive Loss, Net of Tax
	The following table presents the changes in accumulated other comprehensive loss, net of tax by component.
		Foreign Currency Translation Adjustments			Available-for-Sale Securities			Derivative Instruments			Defined Benefit Pension and Other Postretirement Plans			Total
	Balance as of December 31, 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
	Total change for the period	(86.1		)	(0.5		)	0.8			4.5			(81.3		)
	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, 2013 are as follows:
		Three months ended			Nine months ended			Affected Line Item in the Consolidated Statement of Operations
		30-Sep-13			30-Sep-13
	Foreign currency translation adjustments	$	0		$	0
	Gains on available-for-sale securities	0			(1.4		)	Other (expense) income, net
	Losses on derivative instruments	0.4			1.3			Interest expense
	Amortization of defined benefit pension and postretirement plans items 1	2.7			8.2
	Tax effect	(0.9		)	(3.1		)	Provision for income taxes
	Total amount reclassified from accumulated other comprehensive loss, net of tax	$	2.2		$	5
	1	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 9 for further information.
	Share Repurchase Program
	In February 2013, our Board of Directors (the "Board") authorized a new share repurchase program to repurchase from time to time up to $300.0, excluding fees, of our common stock (the "2013 share repurchase program"). In March 2013, the Board authorized an increase in the amount available under our 2013 share repurchase program up to $500.0, excluding fees, of our common stock to be used towards the repurchase of shares resulting from the conversion to common stock of the 4.75% Notes. In February 2012, the Board authorized a share repurchase program to repurchase from time to time up to $300.0, excluding fees, of our common stock (the "2012 share repurchase program"). In November 2012, the Board authorized an increase in the amount available under our 2012 share repurchase program up to $400.0, excluding fees, of our common stock, as a result of the sale of our remaining holdings in Facebook. We may effect such repurchases through open market purchases, trading plans established in accordance with SEC rules, derivative transactions or other means.
	The following table presents our share repurchase activity under our share repurchase programs.
		Nine months ended
		September 30,
		2013			2012
	Number of shares repurchased	19.9			18.6
	Aggregate cost, including fees	$	280.8		$	201.4
	Average price per share, including fees	$	14.12		$	10.85
	As of September 30, 2013, $319.4 remains available for repurchase under the 2013 share repurchase program. The 2013 share repurchase program has no expiration date. We fully utilized the 2012 share repurchase program as of the second quarter of 2013.

Income_Taxes_Notes

Income Taxes (Notes)	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	For the three months ended September 30, 2013, our effective income tax rate of 36.9% was negatively impacted primarily by losses in certain foreign jurisdictions where we receive no tax benefit due to 100% valuation allowances and the net establishment of valuation allowances, primarily in the Continental Europe region. Our effective income tax rate was positively impacted by the recognition of previously unrecognized tax benefits as a result of the settlement of the 2002-2006 NYS audit cycles. For the nine months ended September 30, 2013, our effective income tax rate of 50.7% 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 $10.0 and $20.0 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 1999, or non-U.S. income tax audits for years prior to 2005.

Incentive_Compensation_Plans_N

Incentive Compensation Plans (Notes)	9 Months Ended
	Sep. 30, 2013
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]
Incentive Compensation Plans	Incentive Compensation Plans
	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.
	We issued the following stock-based awards under the 2009 Performance Incentive Plan (the “2009 PIP”) during the nine months ended September 30, 2013.
		Awards	Weighted-average
			grant-date fair value
			(per award)
	Stock options	0.7	$	4.14
	Stock-settled awards	1	$	13.17
	Performance-based awards	1.5	$	11.97
	Total stock-based compensation awards	3.2
	During the nine months ended September 30, 2013, the Compensation Committee granted performance cash awards under the 2009 PIP with a total target value of $86.0. Of this amount, awards with a total target value of $35.6 will be settled in shares upon vesting. The number of shares to be settled on the vesting date will be calculated as the cash value adjusted for performance divided by our stock price on the vesting date. Additionally, during the nine months ended September 30, 2013, the Compensation Committee granted cash awards under the Interpublic Restricted Cash Plan with a total target value of $4.2. Cash awards are amortized over the vesting period, typically three years.

Employee_Benefits_Notes

Employee Benefits (Notes)	9 Months Ended
	Sep. 30, 2013
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,	2013			2012			2013			2012			2013			2012
	Service cost	$	0		$	0		$	2.6		$	3		$	0.1		$	0.1
	Interest cost	1.4			1.6			5.3			5.3			0.4			0.5
	Expected return on plan assets	(1.9		)	(2.0		)	(4.7		)	(4.5		)	0			0
	Settlement and curtailment losses	0			0			0			0.1			0			0
	Amortization of:
	Transition obligation	0			0			0			0			0			0
	Prior service cost (credit)	0			0			0.1			0.1			(0.1		)	0
	Unrecognized actuarial losses	2			1.6			0.7			0.3			0			0
	Net periodic cost	$	1.5		$	1.2		$	4		$	4.3		$	0.4		$	0.6
		Domestic Pension Plan						Foreign Pension Plans						Domestic
														Postretirement Benefit Plan
	Nine months ended September 30,	2013			2012			2013			2012			2013			2012
	Service cost	$	0		$	0		$	7.7		$	8.3		$	0.1		$	0.2
	Interest cost	4.1			4.7			15.9			16.3			1.2			1.7
	Expected return on plan assets	(5.8		)	(5.8		)	(14.3		)	(13.6		)	0			0
	Settlement and curtailment losses	0			0			0			0.1			0			0
	Amortization of:
	Transition obligation	0			0			0			0			0			0.1
	Prior service cost (credit)	0			0			0.2			0.1			(0.1		)	(0.1		)
	Unrecognized actuarial losses	6			4.8			2.1			0.8			0			0
	Net periodic cost	$	4.3		$	3.7		$	11.6		$	12		$	1.2		$	1.9
	During the nine months ended September 30, 2013, we contributed $0.5 and $13.5 of cash to our domestic and foreign pension plans, respectively. For the remainder of 2013, we do not expect to make any additional cash contributions to our domestic pension plan and we expect to contribute approximately $6.0 of cash to our foreign pension plans.

Segment_Information_Notes

Segment Information (Notes)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]
Segment Reporting Disclosure	Segment Information
	We have two reportable segments, IAN and CMG. IAN is comprised of McCann Worldgroup, Draftfcb, Lowe & Partners, IPG Mediabrands 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 operating income. The segment information is presented consistently with the basis described in our 2012 Annual Report on Form 10-K.
	Summarized financial information concerning our reportable segments is shown in the following table.
		Three months ended						Nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Revenue:
	IAN	$	1,370.90		$	1,332.50		$	4,047.70		$	3,999.70
	CMG	329.5			337.9			951.9			893.2
	Total	$	1,700.40		$	1,670.40		$	4,999.60		$	4,892.90
	Segment operating income:
	IAN	$	119.9		$	116.6		$	266.5		$	278.6
	CMG	39.7			34.4			88.3			73.1
	Corporate and other	(18.1		)	(19.6		)	(80.9		)	(83.3		)
	Total	141.5			131.4			273.9			268.4
	Interest expense	(23.7		)	(31.6		)	(98.0		)	(96.9		)
	Interest income	5.8			6.7			18			21.4
	Other (expense) income, net	(46.6		)	1.7			(40.0		)	5.1
	Income before income taxes	$	77		$	108.2		$	153.9		$	198
	Depreciation and amortization of fixed assets and intangible assets:
	IAN	$	32.9		$	30.1		$	95.4		$	88.4
	CMG	3.9			3.9			11.6			10.6
	Corporate and other	3.7			3.4			10.9			9.8
	Total	$	40.5		$	37.4		$	117.9		$	108.8
	Capital expenditures:
	IAN	$	24.5		$	19.9		$	48		$	52.6
	CMG	2.4			11.9			6.5			17.5
	Corporate and other	17.9			9.3			37.1			29.2
	Total	$	44.8		$	41.1		$	91.6		$	99.3
		September 30,			December 31,
		2013			2012
	Total assets:
	IAN	$	10,368.30		$	11,035.30
	CMG	1,182.80			1,073.10
	Corporate and other	(19.1		)	1,385.50
	Total	$	11,532.00		$	13,493.90

Fair_Value_Measurements_Notes

Fair Value Measurements (Notes)	9 Months Ended
	Sep. 30, 2013
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, 2013. The following tables present information about our financial instruments measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		September 30, 2013												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	511		$	0		$	0		$	511		Cash and cash equivalents
	Short-term marketable securities	5.2			0			0			5.2			Marketable securities
	Long-term investments	1.5			0			0			1.5			Other assets
	Total	$	517.7		$	0		$	0		$	517.7
	As a percentage of total assets	4.5		%	0		%	0		%	4.5		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	26		$	26
		December 31, 2012												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	1,806.60		$	0		$	0		$	1,806.60		Cash and cash equivalents
	Short-term marketable securities	16			0			0			16			Marketable securities
	Long-term investments	1.5			0			0			1.5			Other assets
	Total	$	1,824.10		$	0		$	0		$	1,824.10
	As a percentage of total assets	13.5		%	0		%	0		%	13.5		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	25.3		$	25.3
	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 nine months ended September 30, 2013.
	Liabilities	Mandatorily Redeemable Noncontrolling Interests
	Balance at December 31, 2012	$	25.3
	Level 3 additions	1
	Level 3 reductions	(0.9		)
	Realized losses included in net income	0.6
	Balance at September 30, 2013	$	26
	Realized losses 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, 2013 and December 31, 2012, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		September 30, 2013												December 31, 2012
		Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Total long-term debt	$	0		$	1,377.40		$	85.8		$	1,463.20		$	0	$	2,292.40	$	90.8	$	2,383.20
	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 Instruments that are Measured at Fair Value on a Nonrecurring Basis
	Certain non-financial instruments are measured at fair value on a nonrecurring basis, primarily goodwill, intangible assets, and property, 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, 2013
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 2012 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 $420.7 and $410.3 as of September 30, 2013 and December 31, 2012, respectively, and the amount of parent company guarantees primarily relating to credit facilities was $257.6 and $283.4 as of September 30, 2013 and December 31, 2012, respectively.

Recent_Accounting_Standards_No

Recent Accounting Standards (Notes)	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Standards	Recent Accounting Standards
	Comprehensive Income
	In February 2013, the Financial Accounting Standards Board ("FASB") issued amended guidance for presenting comprehensive income, which is effective for us January 1, 2013, and applied prospectively. This amended guidance requires an entity to disclose significant amounts reclassified out of accumulated other comprehensive income by component and their corresponding effect on the respective line items in net income. The adoption of this amended guidance required us to include additional disclosures in our unaudited Consolidated Financial Statements. See Note 6 for further information.
	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. The guidance is effective for us January 1, 2014, and applied prospectively. We do not expect the adoption of this amended guidance to have a significant impact on our Consolidated Financial Statements.

Subsequent_Events_Notes

Subsequent Events (Notes)	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	On October 17, 2013, we converted all outstanding shares of our Series B Preferred Stock into approximately 17.3 shares of our common stock at a conversion rate of 77.8966 shares of common stock per share of Series B Preferred Stock. The Company also paid a nominal cash amount in lieu of fractional shares. The shares of Series B Preferred Stock were previously included as eligible dilutive securities in our calculation of diluted share count, and the approximately 17.3 newly issued common shares will now be included in our basic share count. See Note 3 for further information on the Series B Preferred Stock.

Debt_and_Credit_Arrangements_T

Debt and Credit Arrangements (Tables)	9 Months Ended
	Sep. 30, 2013
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	2013				2012
			Book		Fair		Book		Fair
			Value		Value 1		Value		Value 1
	6.25% Senior Unsecured Notes due 2014 (less unamortized	6.29%	$	351.6	$	369.4	$	352.8	$	372.6
	discount of $0.1)
	2.25% Senior Notes due 2017 (less unamortized	2.30%	299.4		296.7		299.3		297.8
	discount of $0.6)
	4.00% Senior Notes due 2022 (less unamortized	4.13%	247.3		242		247.1		258.7
	discount of $2.7)
	3.75% Senior Notes due 2023 (less unamortized	4.32%	498.6		469.3		498.5		499.7
	discount of $1.4)
	10.00% Senior Unsecured Notes due 2017		0		0		591.9		660.8
	4.75% Convertible Senior Notes due 2023		0		0		200.5		202.8
	Other notes payable and capitalized leases		86.3		85.8		87.3		90.8
	Total long-term debt		1,483.20				2,277.40
	Less: current portion 2		2.2				216.6
	Long-term debt, excluding current portion		$	1,481.00			$	2,060.80
	1	See Note 11 for information on the fair value measurement of our long-term debt.
	2	We included our 4.75% Convertible Senior Notes due 2023 (the “4.75% Notes”) in the current portion of long-term debt on our December 31, 2012 Consolidated Balance Sheet because holders of the 4.75% Notes had an option to require us to repurchase their Notes for cash, stock or a combination, at our election, at par on March 15, 2013. The 4.75% Notes were retired in the first quarter of 2013.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
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,
		2013			2012			2013		2012
	Net income available to IPG common stockholders - basic	$	45.4		$	68.7		$	66.1	$	121.8
	Adjustments: Effect of dilutive securities
	Interest on 4.75% Notes 1	0			1			0		3.1
	Interest on 4.25% Notes 1	0			0			0		0.3
	Net income available to IPG common stockholders - diluted	$	45.4		$	69.7		$	66.1	$	125.2
	Weighted-average number of common shares outstanding - basic	419.7			431.3			419.7		435.5
	Add: Effect of dilutive securities
	Restricted stock, stock options and other equity awards	6.4			8.1			5.1		7.1
	4.75% Notes 1	0			16.7			0		16.7
	4.25% Notes 1	0			0			0		10.4
	Weighted-average number of common shares outstanding - diluted	426.1			456.1			424.8		469.7
	Earnings per share available to IPG common stockholders - basic	$	0.11		$	0.16		$	0.16	$	0.28
	Earnings per share available to IPG common stockholders - diluted	$	0.11		$	0.15		$	0.16	$	0.27
	1	We retired all of our outstanding 4.75% Notes and 4.25% Convertible Senior Notes due 2023 (the “4.25% Notes”) in March 2013 and March 2012, respectively. See Note 2 for further information on our 4.75% Notes. For purposes of calculating diluted earnings per share, the potentially dilutive shares are pro-rated based on the period they were outstanding.
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,
		2013		2012			2013		2012
	4.75% Notes 1	0		0			4.4		0
	Preferred stock outstanding	17.3		16.9			17.3		16.9
	Total	17.3		16.9			21.7		16.9
	Securities excluded from the diluted earnings per share calculation
	because the exercise price was greater than the average market price:
	Stock options 2	0		7.1			0.2		7.1
	1	We retired all of our outstanding 4.75% Notes in March 2013. See Note 2 for further information on our 4.75% Notes. For purposes of calculating diluted earnings per share, the potentially dilutive shares are pro-rated based on the period they were outstanding.
	2	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, 2013
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,
		2013			2012
	Cost of investment: current-year acquisitions	$	51.9		$	154.3
	Cost of investment: prior-year acquisitions	28.5			37
	Less: net cash acquired	(4.7		)	(14.6		)
	Total cost of investment	75.7			176.7
	Operating expense 1	1.6			3.2
	Total cash paid for acquisitions 2	$	77.3		$	179.9
	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 acquired companies.
	2	Of the total cash paid, $27.5 and $36.1 for the nine months ended September 30, 2013, and 2012, 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, $48.2 and $140.6 for the nine months ended September 30, 2013, and 2012, 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,
		2013			2012
	Balance at beginning of period	$	227.2		$	243.4
	Change in related noncontrolling interests balance	(4.9		)	(8.3		)
	Changes in redemption value of redeemable noncontrolling interests:
	Additions	12.5			3
	Redemptions and other	(2.1		)	(14.2		)
	Redemption value adjustments 1	(3.1		)	(3.6		)
	Balance at end of period	$	229.6		$	220.3
	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, 2013
Supplementary Data [Abstract]
Accrued Liabilities	The following table presents the components of accrued liabilities.
		September 30,			December 31,
		2013			2012
	Salaries, benefits and related expenses	$	370.9		$	478.2
	Office and related expenses	52.9			51.6
	Acquisition obligations	9.2			29.5
	Interest	15.9			42.4
	Professional fees	17.6			21.7
	Other	86.8			104.8
	Total accrued liabilities	$	553.3		$	728.2
Other (Expense) Income, Net	Results of operations for the three and nine months ended September 30, 2013 and 2012 include certain items that are not directly associated with our revenue-producing operations.
		Three months ended						Nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Loss on early extinguishment of debt	$	(45.2	)	$	0		$	(45.2	)	$	0
	(Losses) gains on sales of businesses and investments	(0.8		)	(3.4		)	1.9			(5.2		)
	Vendor discounts and credit adjustments	0.1			5			0.6			9.9
	Other (expense) income, net	(0.7		)	0.1			2.7			0.4
	Total other (expense) income, net	$	(46.6	)	$	1.7		$	(40.0	)	$	5.1
Changes In Accumulated Other Comprehensive Loss, Net of Tax	The following table presents the changes in accumulated other comprehensive loss, net of tax by component.
		Foreign Currency Translation Adjustments			Available-for-Sale Securities			Derivative Instruments			Defined Benefit Pension and Other Postretirement Plans			Total
	Balance as of December 31, 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
	Total change for the period	(86.1		)	(0.5		)	0.8			4.5			(81.3		)
	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, 2013 are as follows:
		Three months ended			Nine months ended			Affected Line Item in the Consolidated Statement of Operations
		30-Sep-13			30-Sep-13
	Foreign currency translation adjustments	$	0		$	0
	Gains on available-for-sale securities	0			(1.4		)	Other (expense) income, net
	Losses on derivative instruments	0.4			1.3			Interest expense
	Amortization of defined benefit pension and postretirement plans items 1	2.7			8.2
	Tax effect	(0.9		)	(3.1		)	Provision for income taxes
	Total amount reclassified from accumulated other comprehensive loss, net of tax	$	2.2		$	5
	1	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 9 for further information.
Share Repurchase Program	The following table presents our share repurchase activity under our share repurchase programs.
		Nine months ended
		September 30,
		2013			2012
	Number of shares repurchased	19.9			18.6
	Aggregate cost, including fees	$	280.8		$	201.4
	Average price per share, including fees	$	14.12		$	10.85

Incentive_Compensation_Plans_T

Incentive Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]
Stock-based Compensation Awards	We issued the following stock-based awards under the 2009 Performance Incentive Plan (the “2009 PIP”) during the nine months ended September 30, 2013.
		Awards	Weighted-average
			grant-date fair value
			(per award)
	Stock options	0.7	$	4.14
	Stock-settled awards	1	$	13.17
	Performance-based awards	1.5	$	11.97
	Total stock-based compensation awards	3.2

Employee_Benefits_Tables

Employee Benefits (Tables)	9 Months Ended
	Sep. 30, 2013
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,	2013			2012			2013			2012			2013			2012
	Service cost	$	0		$	0		$	2.6		$	3		$	0.1		$	0.1
	Interest cost	1.4			1.6			5.3			5.3			0.4			0.5
	Expected return on plan assets	(1.9		)	(2.0		)	(4.7		)	(4.5		)	0			0
	Settlement and curtailment losses	0			0			0			0.1			0			0
	Amortization of:
	Transition obligation	0			0			0			0			0			0
	Prior service cost (credit)	0			0			0.1			0.1			(0.1		)	0
	Unrecognized actuarial losses	2			1.6			0.7			0.3			0			0
	Net periodic cost	$	1.5		$	1.2		$	4		$	4.3		$	0.4		$	0.6
		Domestic Pension Plan						Foreign Pension Plans						Domestic
														Postretirement Benefit Plan
	Nine months ended September 30,	2013			2012			2013			2012			2013			2012
	Service cost	$	0		$	0		$	7.7		$	8.3		$	0.1		$	0.2
	Interest cost	4.1			4.7			15.9			16.3			1.2			1.7
	Expected return on plan assets	(5.8		)	(5.8		)	(14.3		)	(13.6		)	0			0
	Settlement and curtailment losses	0			0			0			0.1			0			0
	Amortization of:
	Transition obligation	0			0			0			0			0			0.1
	Prior service cost (credit)	0			0			0.2			0.1			(0.1		)	(0.1		)
	Unrecognized actuarial losses	6			4.8			2.1			0.8			0			0
	Net periodic cost	$	4.3		$	3.7		$	11.6		$	12		$	1.2		$	1.9

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
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,
		2013			2012			2013			2012
	Revenue:
	IAN	$	1,370.90		$	1,332.50		$	4,047.70		$	3,999.70
	CMG	329.5			337.9			951.9			893.2
	Total	$	1,700.40		$	1,670.40		$	4,999.60		$	4,892.90
	Segment operating income:
	IAN	$	119.9		$	116.6		$	266.5		$	278.6
	CMG	39.7			34.4			88.3			73.1
	Corporate and other	(18.1		)	(19.6		)	(80.9		)	(83.3		)
	Total	141.5			131.4			273.9			268.4
	Interest expense	(23.7		)	(31.6		)	(98.0		)	(96.9		)
	Interest income	5.8			6.7			18			21.4
	Other (expense) income, net	(46.6		)	1.7			(40.0		)	5.1
	Income before income taxes	$	77		$	108.2		$	153.9		$	198
	Depreciation and amortization of fixed assets and intangible assets:
	IAN	$	32.9		$	30.1		$	95.4		$	88.4
	CMG	3.9			3.9			11.6			10.6
	Corporate and other	3.7			3.4			10.9			9.8
	Total	$	40.5		$	37.4		$	117.9		$	108.8
	Capital expenditures:
	IAN	$	24.5		$	19.9		$	48		$	52.6
	CMG	2.4			11.9			6.5			17.5
	Corporate and other	17.9			9.3			37.1			29.2
	Total	$	44.8		$	41.1		$	91.6		$	99.3
		September 30,			December 31,
		2013			2012
	Total assets:
	IAN	$	10,368.30		$	11,035.30
	CMG	1,182.80			1,073.10
	Corporate and other	(19.1		)	1,385.50
	Total	$	11,532.00		$	13,493.90

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
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, 2013 and December 31, 2012, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		September 30, 2013												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	511		$	0		$	0		$	511		Cash and cash equivalents
	Short-term marketable securities	5.2			0			0			5.2			Marketable securities
	Long-term investments	1.5			0			0			1.5			Other assets
	Total	$	517.7		$	0		$	0		$	517.7
	As a percentage of total assets	4.5		%	0		%	0		%	4.5		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	26		$	26
		December 31, 2012												Balance Sheet Classification
		Level 1			Level 2			Level 3			Total
	Assets
	Cash equivalents	$	1,806.60		$	0		$	0		$	1,806.60		Cash and cash equivalents
	Short-term marketable securities	16			0			0			16			Marketable securities
	Long-term investments	1.5			0			0			1.5			Other assets
	Total	$	1,824.10		$	0		$	0		$	1,824.10
	As a percentage of total assets	13.5		%	0		%	0		%	13.5		%
	Liabilities
	Mandatorily redeemable noncontrolling interests 1	$	0		$	0		$	25.3		$	25.3
	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 nine months ended September 30, 2013.
	Liabilities	Mandatorily Redeemable Noncontrolling Interests
	Balance at December 31, 2012	$	25.3
	Level 3 additions	1
	Level 3 reductions	(0.9		)
	Realized losses included in net income	0.6
	Balance at September 30, 2013	$	26
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, 2013 and December 31, 2012, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
		September 30, 2013												December 31, 2012
		Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Total long-term debt	$	0		$	1,377.40		$	85.8		$	1,463.20		$	0	$	2,292.40	$	90.8	$	2,383.20

Longterm_Debt_Details

Long-term Debt (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Debt Instrument
Total long-term debt	$1,483,200,000			$1,483,200,000			$2,277,400,000
Less: current portion	2,200,000	[1]		2,200,000	[1]		216,600,000	[1]
Long-term debt, excluding current portion	1,481,000,000			1,481,000,000			2,060,800,000
Loss on early extinguishment of debt	45,200,000		0	45,200,000		0
Exercised Call Option, Shares, Acquired, Net Share Settlement	1,500,000			1,500,000
6.25% Senior Unsecured Notes due 2014
Debt Instrument
Effective Interest Rate	6.29%			6.29%
Book Value	351,600,000			351,600,000			352,800,000
Fair Value	369,400,000	[2]		369,400,000	[2]		372,600,000	[2]
Stated Interest Rate	6.25%			6.25%
Debt Instrument, Unamortized Discount	100,000			100,000
Debt Maturity Date				15-Nov-14
2.25% Senior Notes due 2017
Debt Instrument
Effective Interest Rate	2.30%			2.30%
Book Value	299,400,000			299,400,000			299,300,000
Fair Value	296,700,000	[2]		296,700,000	[2]		297,800,000	[2]
Stated Interest Rate	2.25%			2.25%
Debt Instrument, Unamortized Discount	600,000			600,000
Debt Maturity Date				15-Nov-17
4.00% Senior Notes due 2022
Debt Instrument
Effective Interest Rate	4.13%			4.13%
Book Value	247,300,000			247,300,000			247,100,000
Fair Value	242,000,000	[2]		242,000,000	[2]		258,700,000	[2]
Stated Interest Rate	4.00%			4.00%
Debt Instrument, Unamortized Discount	2,700,000			2,700,000
Debt Maturity Date				15-Mar-22
3.75% Senior Notes due 2023
Debt Instrument
Effective Interest Rate	4.32%			4.32%
Book Value	498,600,000			498,600,000			498,500,000
Fair Value	469,300,000	[2]		469,300,000	[2]		499,700,000	[2]
Stated Interest Rate	3.75%			3.75%
Debt Instrument, Unamortized Discount	1,400,000			1,400,000
Debt Maturity Date				15-Feb-13
10.00% Senior Unsecured Notes due 2017
Debt Instrument
Book Value	0			0			591,900,000
Fair Value	0	[2]		0	[2]		660,800,000	[2]
Stated Interest Rate	10.00%			10.00%
Debt Instrument, Unamortized Discount	0			0
Total cash paid to redeem debt				630,000,000
Redemption Date of 10.00% Notes				15-Jul-13
Loss on early extinguishment of debt				-45,200,000
Write-off of Unamortized Discount				7,300,000
Write-off of Deferred Debt Issuance Cost				7,900,000
Early Redemption Debt Premium of 10.00% Notes				30,000,000
Extinguishment of Debt, Principal Amount				600,000,000
Debt Maturity Date				15-Jul-17
4.75% Notes
Debt Instrument
Book Value	0			0			200,500,000
Fair Value	0	[2]		0	[2]		202,800,000	[2]
Stated Interest Rate	4.75%			4.75%
Extinguishment of Debt, Principal Amount				200,000,000
Debt Maturity Date				15-Mar-23
4.75% Notes, Amount Retired for Cash	199,997,000			199,997,000
Conversion Rate				84.3402
Conversion of convertible notes to common stock, shares				16,900,000
Other notes payable and capitalized leases
Debt Instrument
Book Value	86,300,000			86,300,000			87,300,000
Fair Value	$85,800,000	[2]		$85,800,000	[2]		$90,800,000	[2]
[1]	We included our 4.75% Convertible Senior Notes due 2023 (the b4.75% Notesb) in the current portion of long-term debt on our DecemberB 31, 2012 Consolidated Balance Sheet because holders of the 4.75% Notes had an option to require us to repurchase their Notes for cash, stock or a combination, at our election, at par on MarchB 15, 2013. The 4.75% Notes were retired in the first quarter of 2013.
[2]	See Note 11 for information on the fair value measurement of our long-term debt.

Interest_Rate_Swaps_Details

Interest Rate Swaps (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Debt and Credit Arrangements [Abstract]
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	$300		$300
Amount reclassified from accumulated other comprehensive loss into earnings, derivatives, before tax	0.4	0	1.3	0
Estimated amount reclassified from accumulated other comprehensive loss into earnings within the next twelve months			$1.80

Credit_Facilities_Details

Credit Facilities (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Debt and Credit Arrangements [Abstract]
Credit Agreement expiration date	31-May-16
Credit Agreement current borrowing capacity	$1,000
Line of Credit Facility Limits on Letters of Credit	$200

Convertible_Preferred_Stock_De

Convertible Preferred Stock (Details) (USD $)	Sep. 30, 2013
Convertible Preferred Stock [Abstract]
Convertible Preferred Stock, Interest Rate, Stated Percentage	5.25%
Convertible Preferred Stock, Prior Conversion Ratio	77.1251
Convertible Preferred Stock, Current Conversion Ratio	77.8966
Convertible Preferred Stock, Prior Conversion Price	$12.97
Convertible Preferred Stock, Current Conversion Price	$12.84

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, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Net income available to IPG common stockholders, Basic	$45.40		$68.70		$66.10		$121.80
Net income available to IPG common stockholders, Diluted	45.4		69.7		66.1		125.2
Weighted-average number of common shares outstanding, Basic	419.7		431.3		419.7		435.5
Weighted-average number of common shares outstanding, Diluted	426.1		456.1		424.8		469.7
Earnings per share available to IPG common stockholders, Basic	$0.11		$0.16		$0.16		$0.28
Earnings per share available to IPG common stockholders, Diluted	$0.11		$0.15		$0.16		$0.27
Restricted stock, stock options and other equity awards, Effect of dilutive securities, Incremental common shares	6.4		8.1		5.1		7.1
4.75% Notes
Interest on convertible debt, Effect of dilutive securities	0	[1]	1	[1]	0	[1]	3.1	[1]
Convertible debt, Effect of dilutive securities, Incremental common shares	0	[1]	16.7	[1]	0	[1]	16.7	[1]
4.25% Notes
Interest on convertible debt, Effect of dilutive securities	$0	[1]	$0	[1]	$0	[1]	$0.30	[1]
Convertible debt, Effect of dilutive securities, Incremental common shares	0	[1]	0	[1]	0	[1]	10.4	[1]
[1]	We retired all of our outstanding 4.75% Notes and 4.25% Convertible Senior Notes due 2023 (the b4.25% Notesb) in March 2013 and March 2012, respectively. See Note 2 for further information on our 4.75% Notes. For purposes of calculating diluted earnings per share, the potentially dilutive shares are pro-rated based on the period they were outstanding.

Antidilutive_Shares_Details

Antidilutive Shares (Details)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Antidilutive Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	17.3		16.9		21.7		16.9
Antidilutive Stock Options Excluded Exercise Price Greater Than Average Market Price	0	[1]	7.1	[1]	0.2	[1]	7.1	[1]
4.75% Notes
Antidilutive Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	[2]	0		4.4	[2]	0
Preferred stock outstanding
Antidilutive Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	17.3		16.9		17.3		16.9
[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% Notes in March 2013. See Note 2 for further information on our 4.75% Notes. For purposes of calculating diluted earnings per share, the potentially dilutive shares are pro-rated based on the period they were outstanding.

Acquisitions_Details

Acquisitions (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012
Business Combinations
Number of Businesses Acquired	8		11
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	$67		$205
Business Acquisition, Cost of Investments	75.7		176.7
Cash Acquired from Acquisitions	-4.7		-14.6
Business Acquisition, Operating Expenses	1.6	[1]	3.2	[1]
Business Acquisitions, Total Cash Paid	77.3	[2]	179.9	[2]
Acquisition-related payments	27.5		36.1
Acquisitions, including deferred payments, net of cash acquired	-48.2		-140.6
Current-Year Acquisitions
Business Combinations
Business Acquisition, Cost of Investments	51.9		154.3
Prior-Year Acquisitions
Business Combinations
Business Acquisition, Cost of Investments	$28.50		$37
IAN
Business Combinations
Number of Businesses Acquired	7		7
CMG
Business Combinations
Number of Businesses Acquired	1		4
[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 acquired companies.
[2]	Of the total cash paid, $27.5 and $36.1 for the nine months ended SeptemberB 30, 2013, and 2012, 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, $48.2 and $140.6 for the nine months ended SeptemberB 30, 2013, and 2012, 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, 2013		Sep. 30, 2012
Redeemable Noncontrolling Interest
Balance at beginning of period	$227.20		$243.40
Change in related noncontrolling interests balance	-4.9		-8.3
Changes in redemption value of redeemable noncontrolling interests
Additions	12.5		3
Redemptions and other	-2.1		-14.2
Redemption value adjustments	-3.1	[1]	-3.6	[1]
Balance at end of period	$229.60		$220.30
[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, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accrued Liabilities [Abstract]
Salaries, benefits and related expenses	$370.90	$478.20
Office and related expenses	52.9	51.6
Acquisition obligations	9.2	29.5
Interest	15.9	42.4
Professional fees	17.6	21.7
Other	86.8	104.8
Total accrued liabilities	$553.30	$728.20

Other_Expense_Income_Net_Detai

Other (Expense) Income, Net (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Nonoperating Income (Expense) [Abstract]
Loss on early extinguishment of debt	($45.20)	$0	($45.20)	$0
Losses (gains) on sales of businesses and investments	-0.8	-3.4	1.9	-5.2
Vendor discounts and credit adjustments	0.1	5	0.6	9.9
Other (expense) income, net	-0.7	0.1	2.7	0.4
Total other (expense) income, net	($46.60)	$1.70	($40)	$5.10

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss, Net of Tax (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Changes in Accumulated Other Comprehensive Loss, Net of Tax [Abstract]
Foreign currency translation adjustment, net of tax	($216.20)			($216.20)			($130.10)
Available-for-sale securities adjustment, net of tax	0.3			0.3			0.8
Derivative instruments, net of tax	-11.9			-11.9			-12.7
Defined benefit pension and other postretirement plans, net of tax	-141.5			-141.5			-146
Accumulated other comprehensive loss, net of tax	-369.3			-369.3			-288
Foreign currency translation adjustment, before reclassifications and tax				-86.1
Available-for-sale securities adjustment, before reclassifications and tax				0.7
Derivative instruments, before reclassifications and tax	0		-3.6	0		-22.2
Defined benefit pension and other postretirement plans, before reclassifications and tax				-0.9
Other comprehensive (loss) income, before reclassifications and tax				-86.3
Foreign currency translation adjustments, net of tax				0
Available-for-sale securities, net of tax				-1.2
Derivative instruments, net of tax				0.8
Defined benefit pension and other postretirement plans, net of tax				5.4
Total amount reclassified from accumulated other comprehensive loss, net of tax	2.2			5
Foreign currency translation adjustments				-86.1
Available-for-sale securities, net of tax	-0.1		-25	-0.5		60.5
Derivative instruments, net of tax	0.3		-2.1	0.8		-13
Defined benefit pension and other postretirement plans, net of tax	1.7		1.1	4.5		4
Total other comprehensive loss, net of tax, portion attributable to parent				-81.3
Reclassifications From Accumulated Other Comprehensive Income Loss [Abstract]
Foreign currency translation adjustments, before tax	0			0
Gains (losses) on available-for-sale securities	0		0	1.4		-0.6
Losses on derivative instruments	-0.4		0	-1.3		0
Amortization of defined benefit pension and post retirement plan items	-2.7	[1]	-2	-8.2	[1]	-5.7
Tax effect	-0.9			-3.1
Total amount reclassified from accumulated other comprehensive loss, net of tax	$2.20			$5
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 9 for further information.

Share_Repurchase_Program_Detai

Share Repurchase Program (Details) (USD $)	9 Months Ended			12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Dec. 31, 2012
			2013 Share Repurchase Program	2012 Share Repurchase Program
Share Repurchase Program
Share repurchase program, authorized amount			$300	$300
Share repurchase program, increased authorized amount			500	400
Number of shares repurchased	19.9	18.6
Aggregate cost, including fees	280.8	201.4
Average price per share, including fees	$14.12	$10.85
Share repurchase program, remaining authorized repurchase amount			$319.40

Effective_Income_Tax_Rate_Deta

Effective Income Tax Rate (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Effective income tax rate	36.90%	50.70%
One hundred percent valuation allowance		100.00%

Change_in_Unrecognized_Tax_Ben

Change in Unrecognized Tax Benefits (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Income Tax Disclosure [Abstract]
Estimated unrecognized tax benefit decrease, lower bound	$10
Estimated unrecognized tax benefit decrease, upper bound	$20

Tax_Years_Open_to_Examinations

Tax Years Open to Examinations (Details) (Minimum)	9 Months Ended
	Sep. 30, 2013
Domestic Tax Authority
Income Tax Examination
Open Tax Year	2009
State and Local Jurisdiction
Income Tax Examination
Open Tax Year	1999
Foreign Tax Authority
Income Tax Examination
Open Tax Year	2005

Incentive_Compensation_Plans_D

Incentive Compensation Plans (Details) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013
Incentive compensation plans
Total stock-based compensation awards granted	3.2
Award vesting period	3 years
Stock options
Incentive compensation plans
Granted awards	0.7
Weighted-average grant-date fair value	4.14
Stock-settled awards
Incentive compensation plans
Granted awards	1
Weighted-average grant-date fair value	13.17
Performance-based awards
Incentive compensation plans
Granted awards	1.5
Weighted-average grant-date fair value	11.97
Performance based cash awards
Incentive compensation plans
Total target value of cash awards granted	86
Performance based cash awards settled in shares
Incentive compensation plans
Total target value of cash awards granted	35.6
Time based cash awards
Incentive compensation plans
Total target value of cash awards granted	4.2

Employee_Benefits_Details

Employee Benefits (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Domestic Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	$0	$0	$0	$0
Interest cost	1.4	1.6	4.1	4.7
Expected return on plan assets	-1.9	-2	-5.8	-5.8
Settlement and curtailment losses	0	0	0	0
Amortization of:
Transition obligation	0	0	0	0
Prior service cost (credit)	0	0	0	0
Unrecognized actuarial losses	2	1.6	6	4.8
Net periodic cost	1.5	1.2	4.3	3.7
Defined benefit plan, Contributions made by employer			0.5
Defined benefit plan, Estimated future employer contributions in current fiscal year			0
Foreign Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	2.6	3	7.7	8.3
Interest cost	5.3	5.3	15.9	16.3
Expected return on plan assets	-4.7	-4.5	-14.3	-13.6
Settlement and curtailment losses	0	0.1	0	0.1
Amortization of:
Transition obligation	0	0	0	0
Prior service cost (credit)	0.1	0.1	0.2	0.1
Unrecognized actuarial losses	0.7	0.3	2.1	0.8
Net periodic cost	4	4.3	11.6	12
Defined benefit plan, Contributions made by employer			13.5
Defined benefit plan, Estimated future employer contributions in current fiscal year			6
Domestic Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	0.1	0.1	0.1	0.2
Interest cost	0.4	0.5	1.2	1.7
Expected return on plan assets	0	0	0	0
Settlement and curtailment losses	0	0	0	0
Amortization of:
Transition obligation	0	0	0	0.1
Prior service cost (credit)	-0.1	0	-0.1	-0.1
Unrecognized actuarial losses	0	0	0	0
Net periodic cost	$0.40	$0.60	$1.20	$1.90

Segment_Information_Operations

Segment Information Operations (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segments:
Revenue	$1,700.40	$1,670.40	$4,999.60	$4,892.90
Operating income (loss)	141.5	131.4	273.9	268.4
Interest expense	-23.7	-31.6	-98	-96.9
Interest income	5.8	6.7	18	21.4
Other (expense) income, net	-46.6	1.7	-40	5.1
Income before income taxes	77	108.2	153.9	198
Depreciation and amortization of fixed assets and intangible assets	40.5	37.4	117.9	108.8
Capital expenditures	44.8	41.1	91.6	99.3
IAN
Segments:
Revenue	1,370.90	1,332.50	4,047.70	3,999.70
Operating income (loss)	119.9	116.6	266.5	278.6
Depreciation and amortization of fixed assets and intangible assets	32.9	30.1	95.4	88.4
Capital expenditures	24.5	19.9	48	52.6
CMG
Segments:
Revenue	329.5	337.9	951.9	893.2
Operating income (loss)	39.7	34.4	88.3	73.1
Depreciation and amortization of fixed assets and intangible assets	3.9	3.9	11.6	10.6
Capital expenditures	2.4	11.9	6.5	17.5
Corporate and Other
Segments:
Operating income (loss)	-18.1	-19.6	-80.9	-83.3
Depreciation and amortization of fixed assets and intangible assets	3.7	3.4	10.9	9.8
Capital expenditures	$17.90	$9.30	$37.10	$29.20

Segment_Information_Balance_Sh

Segment Information Balance Sheet (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Segments:
Assets	$11,532	$13,493.90
IAN
Segments:
Assets	10,368.30	11,035.30
CMG
Segments:
Assets	1,182.80	1,073.10
Corporate and Other
Segments:
Assets	($19.10)	$1,385.50

Fair_Value_on_a_Recurring_Basi

Fair Value on a Recurring Basis (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Level 1
Fair value assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents	$511		$1,806.60
Short-term marketable securities	5.2		16
Long-term investments	1.5		1.5
Fair Value of Total Assets, Recurring	517.7		1,824.10
Fair value of assets measured on a recurring basis, percentage of total assets	4.50%		13.50%
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	26	[1]	25.3	[1]
Fair Value, Total
Fair value assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents	511		1,806.60
Short-term marketable securities	5.2		16
Long-term investments	1.5		1.5
Fair Value of Total Assets, Recurring	517.7		1,824.10
Fair value of assets measured on a recurring basis, percentage of total assets	4.50%		13.50%
Mandatorily redeemable noncontrolling interests	$26	[1]	$25.30	[1]
[1]	1B 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, USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Mandatorily redeemable noncontrolling interests
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Balance at beginning of period	$25.30
Level 3 additions	1
Level 3 reductions	-0.9
Realized losses included in net income	0.6
Balance at end of period	$26

Fair_Value_Measurements_Fair_V

Fair Value Measurements Fair Value on a Nonrecurring Basis (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
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	1,377.40	2,292.40
Level 3
Fair value assets and liabilities measured on recurring and nonrecurring basis
Total long-term debt	85.8	90.8
Fair Value, Total
Fair value assets and liabilities measured on recurring and nonrecurring basis
Total long-term debt	$1,463.20	$2,383.20

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Lease guarantees	$420.70	$410.30
Credit facility guarantees	$257.60	$283.40

Subsequent_Events_Details

Subsequent Events (Details)	0 Months Ended	9 Months Ended
	Oct. 17, 2013	Sep. 30, 2013
Subsequent Event [Line Items]
Convertible Preferred Stock, Current Conversion Ratio		77.8966
Subsequent Event Preferred Stock
Subsequent Event [Line Items]
Conversion of Preferred Stock to Common Stock, Date		17-Oct-13
Conversion of convertible notes to common stock, shares	17.3