BALANCE SHEET DETAILS - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	$ 7,967	$ 8,722
Less accumulated depreciation and amortization 1	(7,758)	(7,496)
Property, Plant and Equipment, Net	209	1,226
Computer equipment and purchased software
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	2,548	3,011
Machinery and equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	423	699
Furniture and fixtures
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	1,104	1,115
Leasehold improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	3,892	$ 3,897
San Jose California Facility \| Leasehold improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment	$ 900

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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