Balance Sheet Components - Schedule of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Accounts payable	$ 8,885	$ 5,738
Accrued inventory (in-transit and unvouchered receipts) and trade payables	5,137	4,290
Accrued purchasing card liability	1,762	1,760
Accrued franchise, sales and use taxes	334	281
Other accrued expenses	731	726
Accounts payable and accrued expenses	$ 16,849	$ 12,795