BALANCE SHEET COMPONENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property and equipment
Accumulated depreciation	$ (3,030)	$ (2,720)
Net property and equipment	3,217	2,633
Leasehold improvements
Property and equipment
Property and equipment cost	2,169	2,274
Furniture and fixtures
Property and equipment
Property and equipment cost	1,731	1,516
Computer hardware and office equipment
Property and equipment
Property and equipment cost	1,997	1,563
Construction in progress
Property and equipment
Property and equipment cost	$ 350	$ 0