Significant Balance Sheet Components - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accrued Expenses [Abstract]
Accrued commissions	$ 5,908	$ 4,181
Accrued stock settled bonus	6,608	4,714
Accrued vacation	611	512
Employee stock purchase plan liability	1,811	2,329
Other accrued payroll-related expenses	3,085	2,483
Other accrued liabilities	3,651	4,977
Total accrued expenses	$ 21,674	$ 19,196