Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. federal income taxes:
Current	$ (17)	$ 22	$ 0
Deferred	1,396	1,732	0
Foreign income taxes:
Current	(393)	(123)	(103)
Deferred	(5,177)	(1,003)	0
State income taxes:
Deferred	314	388	0
Total income tax expense (benefit)	$ (3,877)	$ 1,016	$ (103)