Employee Benefits - Rollforward of Defined Benefit Pension Plans Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Pension plan assets at the beginning of the year	$ 23,444	$ 19,460	$ 18,475
Company contributions	3,924	4,405	4,478
Benefit payments	(1,438)	(830)	(1,400)
Actual return on plan assets	684	714	(164)
Contractual termination benefits	0	0	(950)
Foreign currency impact	2,022	(305)	(979)
Pension plan assets at the end of the year	$ 28,636	$ 23,444	$ 19,460