Selected Balance Sheet Components - Schedule of property and equipment, net (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property and equipment, net:
Financing right-of-use lease	$ 65	$ 74
Total property and equipment, gross	29,646	27,630
Less accumulated depreciation	(15,195)	(14,322)
Total property and equipment, net	14,451	13,308
Machinery and equipment
Property and equipment, net:
Total property and equipment, gross	4,514	4,522
Furniture, fixtures and office equipment
Property and equipment, net:
Total property and equipment, gross	1,551	1,551
Computer equipment and software
Property and equipment, net:
Total property and equipment, gross	7,934	7,769
Leasehold improvements
Property and equipment, net:
Total property and equipment, gross	10,616	10,617
Construction in process
Property and equipment, net:
Total property and equipment, gross	$ 4,966	$ 3,097