Employee Benefit Plans - Germany & UK (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
German Pension Plan | Unfunded Plan
Pension plans
Plan assets	$ 0.0
German Pension Plan | Unfunded Plan | Minimum
Pension plans
Qualifying period	10 years
U.K. Pension Plan | Minimum
Pension plans
Minimum required years prior to retirement for eligibility	3 years
Asterion Pension Plan | Minimum
Pension plans
Minimum required years prior to retirement for eligibility	3 years
Norway Pension Plan | Minimum
Pension plans
Minimum required years prior to retirement for eligibility	3 years