Income Tax - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets
Net operating losses	$ 9,666	$ 5,050
Stock-based compensation	890	984
Intangible assets	3,752	4,718
Other	50	67
Total deferred tax assets	14,358	10,819
Valuation allowance	(14,358)	(10,819)
Deferred tax asset, net of valuation allowance	0	0
Net deferred tax liability	$ 0	$ 0