Consolidated Balance Sheet Detail - Schedule of Inventories/Prepaid/PP&E (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventories:
Work-in-process	$ 414	$ 746
Finished goods	185	222
Total	599	968
Prepaid expenses and other:
Prepaid inventory and production costs	422	174
Prepaid insurance	144	122
Prepaid software	18	24
Refundable tax		61
Other	84	91
Total	668	472
Property and equipment, net:
Property and equipment, gross	4,394	4,362
Less: Accumulated depreciation and amortization	(4,273)	(4,165)
Property and equipment, net	121	197
Equipment, furniture and fixtures and leasehold improvements
Property and equipment, net:
Property and equipment, gross	4,265	4,239
Acquired software
Property and equipment, net:
Property and equipment, gross	$ 129	$ 123