Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current tax expense (benefit):
Federal	$ 0.6	$ (0.2)	$ (7.4)
State	(0.2)	(1.1)	0.5
Foreign	18.6	10.9	29.6
Deferred tax expense (benefit):
Federal	(26.9)	(20.1)	15.1
State	(1.0)	(0.5)	0.7
Foreign	5.2	(3.8)	(30.2)
Income tax expense (benefit)	$ (3.7)	$ (14.8)	$ 8.3