Income Taxes - Components of Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ (1,682)
Foreign	2,518	$ (2,246)	$ 1,937
State and local	38	15	(111)
Total current expense (benefit) for income taxes	874	(2,231)	1,826
Deferred:
Federal	205	(35,912)	1,459
Foreign	(27,932)	1,291	(589)
State and local	107	(742)	127
Total deferred expense (benefit) for income taxes	(27,620)	(35,363)	997
Total expense (benefit) for income taxes	$ (26,746)	$ (37,594)	$ 2,823