CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net Income	$ 131.5	$ 113.0
Other comprehensive income, net of tax:
Foreign exchange translation adjustments	7.9	9.9
Income (loss) from derivative agreements	(0.6)	(6.7)
Other comprehensive income (loss)	7.3	3.2
Comprehensive income	$ 138.8	$ 116.2