CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net Income	$ 410.4	$ 413.9	$ 394.4
Other comprehensive income, net of tax:
Foreign exchange translation adjustments	(22.1)	(29.1)	(10.1)
Defined benefit plan adjustments gain (loss)	6.2	(4.7)	7.5
Income (loss) from derivative agreements	4.7	(1.1)	0.3
Other comprehensive income (loss)	(11.2)	(34.9)	(2.3)
Comprehensive income	$ 399.2	$ 379.0	$ 392.1