SELECTED BALANCE SHEET COMPONENTS - PROPERTY PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property and equipment, net:
Total property and equipment, gross	$ 11,140		$ 10,968
Less: Accumulated depreciation	(7,502)		(7,093)
Total, net	3,638		3,875
Depreciation and amortization	400	$ 400
Machinery and equipment
Property and equipment, net:
Total property and equipment, gross	3,150		3,150
Furniture, fixtures and office equipment
Property and equipment, net:
Total property and equipment, gross	931		931
Computer equipment and software
Property and equipment, net:
Total property and equipment, gross	3,266		3,147
Leasehold improvements
Property and equipment, net:
Total property and equipment, gross	3,332		3,332
Construction in process
Property and equipment, net:
Total property and equipment, gross	$ 461		$ 408