Employee Benefit Plan - Change in Benefit Obligation (Details) - Non-U.S. Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in benefit obligations
Benefit obligations	$ 18,173	$ 18,308
Gross service cost	1,164	1,281	$ 1,397
Interest cost	234	199	188
Employee contributions	485	506
Actuarial (gains)/losses	2,763	(672)
Plan Amendment		560
Benefits (paid), net of transfers	(977)	(1,601)
Foreign exchange adjustment	(83)	(408)
Benefit obligations	$ 21,759	$ 18,173	$ 18,308