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	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Retained Earnings (Accumulated Deficit)	Cumulative Effect, Period of Adoption, Adjustment Total IPG Stockholders' Equity
Common stock, shares issued		383.6
Balance at Dec. 31, 2018	$ 2,432.8		$ 38.3	$ 895.9	$ 2,400.1	$ (941.1)	$ 2,393.2	$ 39.6	$ 1.2	$ 1.2	$ 1.2
Net Income Attributable to Parent	656.0
NET INCOME	673.9				656.0		656.0
Net Income Attributable to Nonredeemable Noncontrolling Interest	17.9							17.9
Other comprehensive income	10.4					11.1	11.1	(0.7)
Reclassifications related to redeemable noncontrolling interests	24.6			11.9			11.9	12.7
Distributions to noncontrolling interests	(21.6)							(21.6)
Change in redemption value of RNCI	(0.2)				(0.2)		(0.2)
Common stock dividends	(363.1)				(363.1)		(363.1)
Stock-based compensation, shares		3.8
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	89.1		0.4	88.7			89.1
Exercise of stock options, shares		0.6
Exercise of stock options, Value	4.3		0.1	4.2			4.3
Shares withheld for taxes, shares		(1.0)
Shares withheld for taxes, value	(22.4)		(0.1)	(22.3)			(22.4)
Other	(3.4)			1.1	(4.1)		(5.2)	1.8
Balance at Dec. 31, 2019	2,825.6		38.7	977.3	2,689.9	(930.0)	2,775.9	49.7	$ (6.6)	$ (6.6)	$ (6.6)
Common stock, shares issued		387.0
Net Income Attributable to Parent	351.1
NET INCOME	354.2				351.1		351.1
Net Income Attributable to Nonredeemable Noncontrolling Interest	3.1							3.1
Other comprehensive income	49.1					49.8	49.8	(0.7)
Reclassifications related to redeemable noncontrolling interests	23.3			6.4			6.4	16.9
Distributions to noncontrolling interests	(19.5)							(19.5)
Change in redemption value of RNCI	46.2			41.2	5.0		46.2
Common stock dividends	(402.5)				(402.5)		(402.5)
Stock-based compensation, shares		4.4
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	81.2		0.4	80.8			81.2
Exercise of stock options, shares		0.6
Exercise of stock options, Value	7.2		0.1	7.1			7.2
Shares withheld for taxes, shares		(1.1)
Shares withheld for taxes, value	(22.4)		(0.2)	(22.2)			(22.4)
Other	8.1			(8.7)			8.7	(0.6)
Balance at Dec. 31, 2020	$ 2,943.9		39.0	1,099.3	2,636.9	(880.2)	2,895.0	48.9
Common stock, shares issued	390.9	390.9
Net Income Attributable to Parent	$ 952.8				952.8		952.8
NET INCOME	972.8
Net Income Attributable to Nonredeemable Noncontrolling Interest	20.0							20.0
Other comprehensive income	(15.5)					(14.0)	(14.0)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest								(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
Common stock dividends	(428.0)				(428.0)		(428.0)
Stock-based compensation, shares		3.8
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	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							0.1
Balance at Dec. 31, 2021	$ 3,589.2		$ 39.3	$ 1,226.6	$ 3,154.3	$ (894.2)	$ 3,526.0	$ 63.2
Common stock, shares issued	394.3	394.3