Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ 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	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		387,000
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)
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
Payments for Repurchase of Common Stock	0.0
Common stock dividends	(402.5)				(402.5)		(402.5)
Stock-based compensation, shares		4,400
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	81.2		0.4	80.8			81.2
Exercise of stock options, shares		600
Exercise of stock options, Value	7.2		0.1	7.1			7.2
Shares withheld for taxes, shares		(1,100)
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		390,900
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
Common stock dividends	(428.0)				(428.0)		(428.0)
Stock-based compensation, shares		3,800
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	95.8		0.3	95.5			95.8
Exercise of stock options, shares		600
Exercise of stock options, Value	8.8		0.1	8.7			8.8
Shares withheld for taxes, shares		(1,000)
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
Common stock, shares issued	394,300	394,300
Treasury Stock, Value	$ 0.0
Net Income Attributable to Parent	938.0				938.0		938.0
NET INCOME	956.1
Net Income Attributable to Nonredeemable Noncontrolling Interest	18.1							18.1
Other comprehensive income	(67.8)					(66.2)	(66.2)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest								(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		7,200	700
Retirement of treasury stock	(0.0)			199.2			(0.0)		$ (199.9)
Common stock dividends	(457.2)				(457.2)		(457.2)
Stock-based compensation, shares		3,500
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	71.6		$ 0.4	71.2			71.6
Shares withheld for taxes, shares		(1,000)
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	$ 3,706.0		$ 38.9	$ 1,057.5	$ 3,632.1	$ (960.4)	$ 3,647.9	$ 58.1
Common stock, shares issued	389,600	389,600
Treasury Stock, Value	$ (120.2)