Balance Sheet Details - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
Accrued purchase	$ 430	$ 612
Accrued professional and outside service fees	498	521
Accrued taxes	31	275
Deferred rent	143	61
Lease incentive obligation	425	425
Other	486	725
Total	$ 2,013	$ 2,619