Income Taxes - Reconciliation of 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]
Gross Unrecognized Tax Benefits at January 1	$ 1,061	$ 383
Additions for tax positions taken in the current year	1,346	678
Reductions for tax positions taken in the prior year	(1)	0
Gross Unrecognized Tax Benefits at December 31	$ 2,406	$ 1,061