Income Tax - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets
Net operating losses	$ 10,032	$ 9,666
Stock-based compensation	949	890
Intangible assets	3,748	3,752
Other	77	50
Total deferred tax assets	14,806	14,358
Valuation allowance	(14,497)	(14,358)
Deferred tax asset, net of valuation allowance	309	0
Deferred tax liability	(309)
Net deferred tax liability	$ 0	$ 0