Income Taxes (Provision) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ (0.9)	$ (1.7)	$ (0.8)
State	0.8	(0.7)	(1.6)
Foreign	6.0	5.9	7.1
Current income tax expense	5.9	3.5	4.7
Deferred:
Federal	(13.3)	0.0	(8.7)
State	0.0	0.0	(3.0)
Foreign	0.1	(0.4)	1.9
Deferred income tax benefit	(13.2)	(0.4)	(9.8)
Income tax expense (benefit)	(7.3)	3.1	(5.1)
Domestic	(30.5)	3.9	(33.2)
Foreign	12.4	20.7	28.8
Income (Loss) before income taxes	$ (18.1)	$ 24.6	$ (4.4)