Details of Certain Financial Statement Components - Property, plant and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Property, Plant and Equipment, Net
Property, plant and equipment, gross	$ 2,277		$ 2,105
Less: accumulated depreciation	(1,968)		(1,921)
Total property, plant and equipment, net	309		184
Depreciation expense	37,000	$ 52,000
Furniture, machinery and equipment
Property, Plant and Equipment, Net
Property, plant and equipment, gross	1,857		1,688
Leasehold improvements
Property, Plant and Equipment, Net
Property, plant and equipment, gross	$ 420		$ 417