Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (10.0)	$ (36.0)
Other comprehensive income (loss), net of tax
Unrealized income on derivatives, net of income tax provision of $0.0 and $0.0, respectively		0.5
Employee pension and postretirement benefits, net of income tax provision of $0.1 and $0.4, respectively	0.7	0.6
Foreign currency translation adjustments	11.4	10.1
Total other comprehensive income, net of tax	12.1	11.2
Comprehensive income (loss)	$ 2.1	$ (24.8)