Retirement Plans - Schedule of Changes in Projected Benefit Obligation and Plan Assets, and Net Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Change in plan assets
Company contributions	$ 0.5
United States
Change in benefit obligation
Benefit obligation, beginning of year	64.9	$ 72.8
Interest cost	2.5	2.9
Actuarial (gain) loss	2.5	1.1
Benefits paid	(2.5)	(2.3)
Settlement payments	(3.7)	(9.6)
Foreign exchange rate changes	0.0	0.0
Projected benefit obligation, end of year	63.7	64.9
Change in plan assets
Fair value of plan assets, beginning of year	49.8	59.1
Actual return on plan assets	4.8	2.5
Foreign exchange rate changes	0.0	0.0
Company contributions	0.4	0.1
Benefits paid	(2.5)	(2.3)
Settlement payments	(3.7)	(9.6)
Fair value of plan assets, end of year	48.8	49.8
Funded status of the plan, end of year	(14.9)	(15.1)
Germany
Change in benefit obligation
Benefit obligation, beginning of year	24.1	22.8
Interest cost	0.4	0.6
Actuarial (gain) loss	(0.1)	2.5
Benefits paid	(1.0)	(0.9)
Settlement payments	0.0	0.0
Foreign exchange rate changes	3.4	(0.9)
Projected benefit obligation, end of year	26.8	24.1
Change in plan assets
Fair value of plan assets, beginning of year	15.2	18.6
Actual return on plan assets	1.1	0.7
Foreign exchange rate changes	2.1	(0.5)
Company contributions	0.1	(2.7)
Benefits paid	(1.0)	(0.9)
Settlement payments	0.0	0.0
Fair value of plan assets, end of year	17.5	15.2
Funded status of the plan, end of year	$ (9.3)	$ (8.9)