Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current tax expense:
U.S. federal	$ (188)	$ (1,074)	$ 3,406
State and local	82	83	72
Foreign	8,217	10,829	8,304
Total current	8,111	9,838	11,782
Deferred tax (benefit) expense:
U.S. federal	0	3,961	9,495
State and local	0	1,930	(369)
Foreign	(1,339)	(1,487)	(3,297)
Total deferred	(1,339)	4,404	5,829
Total provision for income taxes	$ 6,772	$ 14,242	$ 17,611