Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accrued liabilities
Accrued payroll-related expenses	$ 757	$ 1,045
Deferred licensing revenue	104	229
Deferred rent	240	248
Accrued sales commissions payable to sales representatives	97	193
Other	713	96
Total accrued liabilities	$ 1,911	$ 1,811