CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income before allocation to noncontrolling interests	$ 133.6	$ 335.5	$ 172.5
Other comprehensive (loss) income, net of tax
Currency translation adjustment	11.5	(41.6)	86.9
Changes in pension and postretirement plan assets and benefit obligation, net of tax	(47.7)	(26.2)	9.2
Other comprehensive (loss) income, net of tax	(36.2)	(67.8)	96.1
Comprehensive income before allocation to noncontrolling interests	97.4	267.7	268.6
Less: Noncontrolling interests in comprehensive (loss) income	(0.1)	(0.3)	0.7
Comprehensive income attributable to common shareholders	$ 97.5	$ 268.0	$ 267.9