Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
NET LOSS	$ (9.5)	$ (16.1)
Foreign currency translation:
Foreign currency translation adjustments	8.3	22.4
Reclassification adjustments recognized in net loss	1.2	12.5
Foreign currency transaction and translation adjustment, net of tax	9.5	34.9
Derivative instruments:
Recognition of previously unrealized losses in net loss	0.6	0.5
Income tax effect	(0.1)	(0.2)
Net unrecognized gains/losses on derivative instruments, net of tax	0.5	0.3
Defined benefit pension and other postretirement plans:
Amortization of unrecognized losses, transition obligation and prior service cost included in net income	1.7	1.9
Settlement and curtailment losses included in net income	0.0	0.2
Other	(0.3)	0.1
Income tax effect	(0.1)	(0.1)
Defined benefit pension and other postretirement plans adjustment, net of tax	1.3	2.1
Other comprehensive income, net of tax	11.3	37.3
TOTAL COMPREHENSIVE INCOME	1.8	21.2
Less: comprehensive loss attributable to noncontrolling interests	(1.6)	(1.7)
COMPREHENSIVE INCOME ATTRIBUTABLE TO IPG	$ 3.4	$ 22.9