Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Tax benefit of operating loss carry forward	$ 7,942	$ 11,612
Reserves and allowances	1	12
Accrued expenses	73	35
Charitable contributions	134	198
Stock-based compensation	802	1,098
Fixed assets	0	102
Goodwill	144	0
Intangible amortization	61	0
Texas margin tax temporary credit	233	239
Total deferred tax assets	9,390	13,296
Valuation allowance	(9,390)	(13,192)
Net deferred tax assets	0	104
Deferred tax liabilities:
Goodwill	0	230
Intangible amortization	0	104
Total deferred tax liabilities	0	334
Net deferred tax liability	$ 0	$ (230)