Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 2.5	$ 1.0	$ 5.2
State	1.0	0.9	0.5
International	29.4	33.3	34.5
Current income tax provision	32.9	35.2	40.2
Deferred:
Federal and state	21.8	(13.2)	7.7
International	(0.3)	4.3	(0.7)
Deferred income tax provision	21.5	(8.9)	7.0
Income tax expense	$ 54.4	$ 26.3	$ 47.2