Interest and Other Income (Expense), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and Other Income (Expense), Net
Interest income	$ 0.8	$ 0.3	$ 1.2
Interest expense	(15.4)	(13.2)	(13.0)
Exchange gains (losses) on foreign currency transactions	(5.5)	4.1	(5.5)
Gain on bargain purchase	0.6	9.2
(Loss) gain on disposal of product line			(0.2)
Other	2.6		(0.2)
Interest and other income (expense), net	$ (16.9)	$ 0.4	$ (17.7)