CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 163.6	$ 219.6	$ 78.3	$ 333.2
Foreign currency translation:
Foreign currency translation adjustments	137.4	(29.0)	202.2	(81.3)
Reclassification adjustments recognized in net income	0.0	0.0	20.3	0.0
Foreign currency transaction and translation adjustment, net of tax	137.4	(29.0)	222.5	(81.3)
Derivative instruments:
Recognition of previously unrealized net gain in net income	(1.0)	(0.9)	(2.0)	(1.8)
Income tax effect	0.2	0.2	0.5	0.4
Other comprehensive income (loss), cash flow hedge, gain (loss), after reclassification and tax	(0.8)	(0.7)	(1.5)	(1.4)
Defined benefit pension and other postretirement plans:
Net actuarial (loss) gain for the period	(0.2)	(0.5)	(0.4)	0.3
Amortization of unrecognized losses, transition obligation and prior service cost included in net income	2.3	1.8	4.5	3.7
Settlement losses included in net income	0.0	(0.1)	0.0	(0.1)
Other	0.1	0.2	(0.1)	0.3
Income tax effect	(0.5)	(0.3)	(1.0)	(0.8)
Defined benefit pension and other postretirement plans adjustment, net of tax	1.7	1.1	3.0	3.4
Other comprehensive income (loss), net of tax	138.3	(28.6)	224.0	(79.3)
TOTAL COMPREHENSIVE INCOME	301.9	191.0	302.3	253.9
Less: comprehensive income attributable to non-controlling interests	1.8	4.8	2.1	6.8
COMPREHENSIVE INCOME ATTRIBUTABLE TO IPG	$ 300.1	$ 186.2	$ 300.2	$ 247.1