Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 11.5	$ 9.6	$ 11.2	$ (25.9)
Other comprehensive income (loss), net of tax
Unrealized income (expense) on derivatives, net of income tax provision of $0.0, $0.0, $0.0 and $0.0, respectively	1.3		(2.0)	0.6
Employee pension and postretirement benefits, net of income tax provision of $0.8, $3.3, $0.8 and $4.1, respectively	4.2	5.7	5.6	6.8
Foreign currency translation adjustments	(7.1)	14.2	(22.5)	47.4
Total other comprehensive income (loss), net of tax	(1.6)	19.9	(18.9)	54.8
Comprehensive income (loss)	$ 9.9	$ 29.5	$ (7.7)	$ 28.9