Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock, Shares	Common Stock, Amount	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss, Net of Tax	Treasury Stock [Member]	Total IPG Stockholders' Equity	Noncontrolling Interests
Common Stock, shares		394.3
Balance at Dec. 31, 2021	$ 3,589.2		$ 39.3	$ 1,226.6	$ 3,154.3	$ (894.2)	$ 0.0	$ 3,526.0	$ 63.2
Net income	160.9
Net income available to IPG common stockholders	159.4				159.4			159.4
Net income attributable to noncontrolling interest	1.5								1.5
Other comprehensive loss	2.2					1.9		1.9
Other comprehensive loss, attributable to noncontrolling interest									0.3
Reclassifications related to redeemable noncontrolling interests	1.3			1.2				1.2	0.1
Distributions to noncontrolling interests	(3.1)								3.1
Change in redemption value of redeemable noncontrolling interests	(1.4)				(1.4)			(1.4)
Repurchases of Common Stock	(63.1)						(63.1)	(63.1)
Common stock dividends	(115.6)				(115.6)			(115.6)
Stock-based compensation, shares		2.8
Stock-based compensation, value	18.0		0.5	17.5				18.0
Shares withheld for taxes, shares		(1.0)
Shares withheld for taxes, value	(37.0)		0.1	36.9				37.0
Balance at Mar. 31, 2022	3,548.8		39.7	1,206.0	3,196.7	(892.3)	(63.1)	3,487.0	61.8
Common Stock, shares		396.1
Common Stock, shares		389.6
Balance at Dec. 31, 2022	3,706.0		38.9	1,057.5	3,632.1	(960.4)	(120.2)	3,647.9	58.1
Net income	132.1
Net income available to IPG common stockholders	126.0				126.0			126.0
Net income attributable to noncontrolling interest	6.1								6.1
Other comprehensive loss	23.5					23.8		23.8
Other comprehensive loss, attributable to noncontrolling interest									(0.3)
Reclassifications related to redeemable noncontrolling interests	0.3								0.3
Distributions to noncontrolling interests	(3.1)								3.1
Repurchases of Common Stock	(77.8)						(77.8)	(77.8)
Common stock dividends	(120.0)				(120.0)			(120.0)
Stock-based compensation, shares		3.8
Stock-based compensation, value	18.2		0.4	17.8				18.2
Shares withheld for taxes, shares		(1.6)
Shares withheld for taxes, value	(58.8)		0.2	58.6				58.8
Other	0.2								(0.2)
Balance at Mar. 31, 2023	$ 3,620.0		$ 39.1	$ 1,016.7	$ 3,638.1	$ (936.6)	$ (198.0)	$ 3,559.3	$ 60.7
Common Stock, shares		391.8