Employee Benefit Plans - Change in Benefit Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Present value of projected benefit obligation at the beginning of the year	$ 67,623	$ 72,864
Actuarial (gain)/ loss	11,983	(198)
Service cost	588	604	$ 772
Interest cost	1,694	1,758	1,723
Benefits paid	(1,346)	(925)
Other	0	126
Curtailments, settlements, special and contractual termination benefits	0	(2,154)
Currency translation	(1,153)	(4,452)
Present value of projected benefit obligation at the end of the year	$ 79,389	$ 67,623	$ 72,864