Balance Sheet Components - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities And Other Liabilities [Abstract]
Accrued payroll	$ 3,918	$ 3,353
Accrued vacation	1,699	1,323
Employee stock purchase plan contributions	1,496
Other liabilities	798	543
Total accrued expenses and other liabilities	$ 7,911	$ 5,219