Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating loss carryforwards	$ 28,871	$ 19,323
Tax credits	2,193	1,512
Accrued liabilities	754	712
Stock based compensation	536	21
Other	509	241
Total deferred tax assets	32,863	21,809
Valuation allowance	$ (32,863)	$ (21,809)