Employee Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 3,622	$ 2,258
Prior service cost	273	0
Deferred income tax asset	(670)	(375)
Accumulated other comprehensive loss	3,225	1,883
U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	45,358	39,569
Prior service cost	0	0
Deferred income tax asset	(9,524)	(13,849)
Accumulated other comprehensive loss	$ 35,834	$ 25,720