Income Taxes - Deferred taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net federal operating loss carry forward	$ 4,748	$ 4,400
Net state operating loss carry forward	599	404
Accruals	256	178
Intangibles	536	114
Stock options	1,557
Deferred rent	862
Other	182	245
Deferred tax assets	8,740	5,341
Less: valuation allowances	(7,389)	(4,489)	$ (4,626)
Deferred tax assets after valuation allowance	1,351	852
Deferred tax liabilities:
Fixed assets	(1,351)	(556)
Debt discount		(295)
Indefinite-lived intangibles	(832)	(335)
Deferred tax liabilities	(2,183)	(1,186)
Net deferred tax liabilities	$ (832)	$ (334)