CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net Income	$ 124.0	$ 120.4	$ 348.6	$ 301.3
Other comprehensive income, net of tax:
Foreign exchange translation adjustments	(2.6)	(13.1)	0.8	(17.8)
Defined benefit plan adjustments gain (loss)	0.0	0.0	0.0	3.9
Income (loss) from derivative agreements	0.8	2.3	(6.7)	3.7
Other comprehensive income (loss)	(1.8)	(10.8)	(5.9)	(10.2)
Comprehensive income	$ 122.2	$ 109.6	$ 342.7	$ 291.1