Income Taxes (Details 1) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Deferred rent	$ 25	$ 11
Deferred revenue		85
Federal and state net operating loss carryforwards	10,818	10,727
Stock-based compensation	4,831	6,493
Compensation accruals and other	553	36
Total deferred tax assets	16,227	17,352
Valuation allowance	(16,144)	(17,277)
Net deferred tax assets	83	75
Deferred tax liabilities:
Total deferred tax liabilities	(83)	(75)
Net deferred tax asset (liability)
Property and equipment	$ (83)	$ (75)