Interest and Other Income (Expense), Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest and Other Income (Expense), Net
Interest expense, net	$ (2.6)	$ (3.8)	$ (6.0)	$ (7.5)
Exchange losses on foreign currency transactions	(1.5)	(1.9)	(1.0)	(4.2)
Pension components	(1.3)	(1.8)	(1.3)	(1.8)
Other	(0.1)	2.4	0.5	2.4
Interest and other income (expense), net	$ (5.5)	$ (5.1)	$ (7.8)	$ (11.1)