Income Taxes - Components of Provision for Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal
Current	$ 190	$ 130	$ 110
Deferred	(3,577)	4,327	954
Total Federal	(3,387)	4,457	1,064
State and Local
Current	838	(26)	840
Deferred	765	312	1,312
Total State and Local	1,603	286	2,152
Foreign
Current	2,959	3,677	3,787
Deferred	(1,688)	57	1,882
Total Foreign	1,271	3,734	5,669
Total (Benefit) Provision	$ (513)	$ 8,477	$ 8,885