Balance Sheet Components - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accrued Liabilities And Other Liabilities [Abstract]
Accrued payroll	$ 5,611	$ 3,918
Accrued vacation	2,173	1,699
Employee stock purchase plan contributions	397	1,496
Other liabilities	857	798
Total accrued expenses and other liabilities	$ 9,038	$ 7,911