Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net Income	$ 61.6	$ 64.6
Currency translation adjustments	31.6	9.1
Net unrealized pension and other benefit actuarial gains and prior service credits	(0.8)	(0.2)
Net unrealized gains on financial instruments (net of tax)	4.8	7.4
Total other comprehensive income	35.6	16.3
Comprehensive income	$ 97.2	$ 80.9