Accumulated Other Comprehensive Income (Loss) - Change in the Components of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity [Abstract]
Derivative Instruments Gain (Loss), Pretax	$ (7.8)	$ 21.0	$ (1.0)
Derivative Instruments Gain (Loss), Tax Effect	2.9	(8.0)	0.3
Derivative Instruments Gain (Loss), Net Amount	(4.9)	13.0	(0.7)
Pension and Postretirement Benefit Plans, Pretax Amount	12.3	7.9	40.0
Pension and Postretirement Benefit Plans, Tax Effect	(3.5)	(3.9)	(13.2)
Pension and Postretirement Benefit Plans, Net Amount	8.8	4.0	26.8
Currency Translation Adjustment, Pretax Amount	44.9	(58.9)	(37.2)
Currency Translation Adjustment, Tax Effect	0.0	0.0	0.0
Currency Translation Adjustment, Net Amount	44.9	(58.9)	(37.2)
Other Comprehensive Income (Loss), Pretax Amount	49.4	(30.0)	1.8
Other Comprehensive Income (Loss), Tax Effect	(0.6)	(11.9)	(12.9)
Net Current-period Other Comprehensive (Loss) Income	$ 48.8	$ (41.9)	$ (11.1)