BALANCE SHEET COMPONENTS - SCHEDULE OF ACCRUED EXPENSES AND OTHER LIABILITIES(Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accrued Liabilities and Other Liabilities [Abstract]
Accrued payroll	$ 6,291	$ 6,072
Accrued vacation	2,582	2,069
Employee stock purchase plan contributions	1,374	1,171
Other liabilities	1,476	1,158
Total accrued expenses and other liabilities	$ 11,723	$ 10,470