Consolidated Statements of Stockholders' Equity and Comprehensive Income (Loss) (USD $) In Millions	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss, Net of Tax	Treasury Stock	Total IPG Stockholders' Equity	Noncontrolling Interests
Beginning balance at Dec. 31, 2009	$ 2,536.3	$ 525.0	$ 47.1	$ 2,441.0	$ (324.8)	$ (176.6)	$ (14.0)	$ 2,497.7	$ 38.6
Beginning balance, shares at Dec. 31, 2009			486.5
Net income	58.4				63.2			63.2	(4.8)
Foreign currency translation adjustments, net of tax	9.2					8.3		8.3	0.9
Changes in market value of securities available-for-sale, net of tax	0.2					0.2		0.2
Recognition of previously unrealized loss on securities available-for-sale, net of tax	(0.2)					(0.2)		(0.2)
Unrecognized losses, transition obligation and prior service cost, net of tax	6.5					6.5		6.5
Total comprehensive income	74.1							78.0	(3.9)
Reclassifications related to redeemable noncontrolling interests	18.6								18.6
Noncontrolling interest transactions	(24.9)			(26.0)				(26.0)	1.1
Distributions to noncontrolling interests	(18.2)								(18.2)
Change in redemption value of redeemable noncontrolling interests	(5.6)			(5.6)				(5.6)
Repurchase of preferred stock	(267.6)	(303.5)		35.9				(267.6)
Preferred stock dividends	(12.7)			(12.7)				(12.7)
Stock-based compensation	41.2			41.2				41.2
Restricted stock, net of forfeitures, shares			2.3
Restricted stock, net of forfeitures	(11.1)		0.3	(11.4)				(11.1)
Other, shares			0.3
Other	1.4		0	2.3			(0.1)	2.2	(0.8)
Ending balance at Sep. 30, 2010	2,331.5	221.5	47.4	2,464.7	(261.6)	(161.8)	(14.1)	2,296.1	35.4
Ending balance, shares at Sep. 30, 2010			489.1
Beginning balance at Dec. 31, 2010	2,566.9	221.5	47.5	2,456.8	(63.7)	(119.0)	(14.1)	2,529.0	37.9
Beginning balance, shares at Dec. 31, 2010			489.5
Net income	273.2				270.4			270.4	2.8
Foreign currency translation adjustments, net of tax	(71.8)					(70.1)		(70.1)	(1.7)
Changes in market value of securities available-for-sale, net of tax	0.1					0.1		0.1
Recognition of previously unrealized loss on securities available-for-sale, net of tax	0.2					0.2		0.2
Unrecognized losses, transition obligation and prior service cost, net of tax	7.2					7.2		7.2
Total comprehensive income	208.9							207.8	1.1
Reclassifications related to redeemable noncontrolling interests	15.8								15.8
Noncontrolling interest transactions	(2.7)			0.2				0.2	(2.9)
Distributions to noncontrolling interests	(17.4)								(17.4)
Change in redemption value of redeemable noncontrolling interests	(20.7)			(20.7)				(20.7)
Repurchase of common stock	(269.0)						(269.0)	(269.0)
Common stock dividends	(84.4)			(56.8)	(27.6)			(84.4)
Preferred stock dividends	(8.7)			(5.8)	(2.9)			(8.7)
Stock-based compensation	36.5			36.5				36.5
Exercise of stock options, shares			1.2
Exercise of stock options	12.0		0.1	11.9				12.0
Restricted stock, net of forfeitures, shares			0.4
Restricted stock, net of forfeitures	(28.3)		0.6	(28.9)				(28.3)
Other, shares			0.3
Other	4.6		0	4.2				4.2	0.4
Ending balance at Sep. 30, 2011	$ 2,413.5	$ 221.5	$ 48.2	$ 2,397.4	$ 176.2	$ (181.6)	$ (283.1)	$ 2,378.6	$ 34.9
Ending balance, shares at Sep. 30, 2011			491.4