Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 22.2	$ 17.2
Changes in cumulative translation adjustment, net of tax of $(0.1) million and $(0.1) million respectively	6.4	3.5
Changes in unrealized gains on derivative instruments, net of tax of $(0.2) million and $(0.1) million respectively	0.9	0.2
Amortization of prior service credit, net of tax of $0.1 million and $0.1 million respectively	(0.2)	(0.2)
Amortization of actuarial net losses, net of tax of $(0.1) million and $(0.2) million respectively	0.4	1.0
Total other comprehensive income	7.5	4.5
Total comprehensive income	$ 29.7	$ 21.7