Background and Basis of Presentation - Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 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	$ 275.0	$ 203.8
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 Facilities (variable rates)
Fair Value of Financial Instruments
Total debt	93.0	21.6
Carrying Value | Secured debt | German loan agreement (2.45% fixed rate)
Fair Value of Financial Instruments
Total debt	3.4	3.5
Carrying Value | Secured debt | German loan agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Total debt	3.6	3.7
Level 2 | Fair Value
Fair Value of Financial Instruments
Total debt	274.5	203.2
Level 2 | Fair Value | Senior notes | 2021 Senior Notes (5.25% fixed rate)
Fair Value of Financial Instruments
Total debt	174.3	174.3
Level 2 | Fair Value | Secured debt | Global Revolving Credit Facilities (variable rates)
Fair Value of Financial Instruments
Total debt	93.0	21.6
Level 2 | Fair Value | Secured debt | German loan agreement (2.45% fixed rate)
Fair Value of Financial Instruments
Total debt	3.5	3.6
Level 2 | Fair Value | Secured debt | German loan agreement (1.45% fixed rate)
Fair Value of Financial Instruments
Total debt	$ 3.7	$ 3.7