Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Accrued expenses	$ 574	$ 556
Tax credits	318
Other	108	27
NOL carryforward	12,666	15,725
Total deferred tax assets	13,666	16,308
Valuation allowance	(13,406)	(16,130)
Net deferred tax assets	260	178
Deferred tax (liabilities)
Property and equipment	(161)	(210)
Total deferred tax liability	(161)	(210)
Net deferred tax assets	$ 99
Net deferred tax (liabilities)		$ (32)