Employee Benefit Plans - Components of Net Periodic Benefit Expense (Details) - Defined Benefit Pension Plans - Germany - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan
Service cost	$ 0.3	$ 0.3	$ 0.8	$ 0.7
Interest cost	0.2	0.3	0.6	0.8
Amortization of net actuarial gains		(0.1)		(0.2)
Expected return on plan assets				(0.1)
Net periodic benefit expense	$ 0.5	$ 0.5	$ 1.4	$ 1.2