Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning of year	$ 62	$ 168
Gross decreases—tax positions in prior period	0	(107)
Interest accrual	0	1
Unrecognized tax benefits, end of year	$ 62	$ 62