Background and Basis of Presentation - Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Senior notes | 2021 Senior Notes (5.25% fixed rate)
Fair Value of Financial Instruments
Fixed rate of interest	5.25%
Secured debt | German loan agreement (2.45% fixed rate)
Fair Value of Financial Instruments
Fixed rate of interest	2.45%
Secured debt | German loan agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Fixed rate of interest	1.45%
Carrying Value
Fair Value of Financial Instruments
Total debt	$ 391.0	$ 203.8
Carrying Value | Line of credit | Term Loan B (variable rates)
Fair Value of Financial Instruments
Total debt		0.0
Carrying Value | Senior notes | Term Loan B (variable rates)
Fair Value of Financial Instruments
Total debt	200.0
Carrying Value | Senior notes | 2021 Senior Notes (5.25% fixed rate)
Fair Value of Financial Instruments
Total debt	175.0	175.0
Carrying Value | Secured debt | Global Revolving Credit Facility (variable rates)
Fair Value of Financial Instruments
Total debt	10.1	21.6
Carrying Value | Secured debt | German loan agreement (2.45% fixed rate)
Fair Value of Financial Instruments
Total debt	2.9	3.5
Carrying Value | Secured debt | German loan agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Total debt	3.0	3.7
Level 2 | Fair Value
Fair Value of Financial Instruments
Total debt	391.1	203.2
Level 2 | Fair Value | Line of credit | Term Loan B (variable rates)
Fair Value of Financial Instruments
Total debt	200.0	0.0
Level 2 | Fair Value | Senior notes | 2021 Senior Notes (5.25% fixed rate)
Fair Value of Financial Instruments
Total debt	175.0	174.3
Level 2 | Fair Value | Secured debt | Global Revolving Credit Facility (variable rates)
Fair Value of Financial Instruments
Total debt	10.1	21.6
Level 2 | Fair Value | Secured debt | German loan agreement (2.45% fixed rate)
Fair Value of Financial Instruments
Total debt	3.0	3.6
Level 2 | Fair Value | Secured debt | German loan agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Total debt	$ 3.0	$ 3.7