Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock, Shares Issued [Member]	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss, Net of Tax	Total IPG Stockholders' Equity	Noncontrolling Interests	Treasury Stock
Common stock, shares issued		390.9
Balance at Dec. 31, 2020	$ 2,943.9		$ 39.0	$ 1,099.3	$ 2,636.9	$ (880.2)	$ 2,895.0	$ 48.9	$ 0.0
Net Income Attributable to Parent	952.8
NET INCOME	972.8				952.8		952.8
Net Income Attributable to Nonredeemable Noncontrolling Interest	20.0							20.0
Other comprehensive income	(15.5)					(14.0)	(14.0)	(1.5)
Reclassifications related to redeemable noncontrolling interests	22.7			11.3			11.3	11.4
Distributions to noncontrolling interests	(15.5)							(15.5)
Change in redemption value of RNCI	32.4			39.8	(7.4)		32.4
Payments for Repurchase of Common Stock	0.0
Retirement of treasury stock, shares		0.0
Common stock dividends	(428.0)				(428.0)		(428.0)
Stock-based compensation, shares		3.8
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	95.8		0.3	95.5			95.8
Exercise of stock options, shares		0.6
Exercise of stock options, Value	8.8		0.1	8.7			8.8
Shares withheld for taxes, shares		(1.0)
Shares withheld for taxes, value	(28.1)		(0.1)	(28.0)			(28.1)
Other	(0.1)			(0.0)			0.0	(0.1)
Balance at Dec. 31, 2021	3,589.2		39.3	1,226.6	3,154.3	(894.2)	3,526.0	63.2	0.0
Common stock, shares issued		394.3
Net Income Attributable to Parent	938.0
NET INCOME	956.1				938.0		938.0
Net Income Attributable to Nonredeemable Noncontrolling Interest	18.1							18.1
Other comprehensive income	(101.1)					(99.5)	(99.5)	(1.6)
Reclassifications related to redeemable noncontrolling interests	(2.6)			(3.1)			(3.1)	0.5
Distributions to noncontrolling interests	(12.3)							(12.3)
Change in redemption value of RNCI	(3.0)				(3.0)		(3.0)
Payments for Repurchase of Common Stock	320.1						320.1		(320.1)
Retirement of treasury stock, shares		7.2
Retirement of treasury stock	0.0		0.7	199.2			0.0		(199.9)
Common stock dividends	(457.2)				(457.2)		(457.2)
Stock-based compensation, shares		3.5
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	71.6		0.4	71.2			71.6
Shares withheld for taxes, shares		(1.0)
Shares withheld for taxes, value	(38.8)		(0.1)	(38.7)			(38.8)
Other	(9.1)			(0.7)			0.7	(9.8)
Balance at Dec. 31, 2022	$ 3,672.7		38.9	1,057.5	3,632.1	(993.7)	3,614.6	58.1	(120.2)
Common stock, shares issued	389.6	389.6
Net Income Attributable to Parent	$ 1,098.4				1,098.4		1,098.4
NET INCOME	1,118.1
Net Income Attributable to Nonredeemable Noncontrolling Interest	19.7							19.7
Other comprehensive income	47.3					47.5	47.5
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest								(0.2)
Reclassifications related to redeemable noncontrolling interests	0.3							0.3
Distributions to noncontrolling interests	(17.7)							(17.7)
Change in redemption value of RNCI	2.6				2.6		2.6
Payments for Repurchase of Common Stock	(350.2)
Retirement of treasury stock, shares		9.3
Retirement of treasury stock	(0.0)		0.9	339.5			(0.0)		(340.4)
Payments for Repurchase of Common Stock, including excise taxes	(352.7)						(352.7)		(352.7)
Common stock dividends	(478.6)				(478.6)		(478.6)
Stock-based compensation, shares		4.4
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	70.1		0.5	69.6			70.1
Shares withheld for taxes, shares		(1.7)
Shares withheld for taxes, value	(59.3)		(0.2)	(59.1)			(59.3)
Other	(1.0)			(0.0)			0.0	(1.0)
Balance at Dec. 31, 2023	$ 4,003.8		$ 38.3	$ 728.5	$ 4,254.5	$ (946.2)	$ 3,942.6	$ 61.2	$ (132.5)
Common stock, shares issued	383.0	383.0