Income Taxes - Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current tax expense:
U.S. federal	$ 1,748	$ 2,726	$ 47
State and local	374	189	49
Foreign	4,150	9,028	8,127
Total current	6,272	11,943	8,223
Deferred tax (benefit) expense:
U.S. federal	(1,416)	(4,588)	(687)
State and local	(356)	(87)	74
Foreign	304	(466)	307
Total deferred	(1,468)	(5,141)	(306)
Total provision for income taxes	$ 4,804	$ 6,802	$ 7,917