Balance Sheet Components (Accured liab) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Balance Sheet Components
Accrued expenses	$ 12,665	$ 8,560
Accrued rent	419	551
Deferred lease obligation	71	99
Accrued interest	692	764
Sales tax payable	177	367
Total other accrued liabilities	$ 14,024	$ 10,341