Selected Balance Sheet Components - Schedule of property and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property and equipment, net:
Financing right-of-use lease	$ 83		$ 83		$ 111
Total property and equipment, gross	25,361		25,361		19,019
Less accumulated depreciation	(13,542)		(13,542)		(11,386)
Property and equipment, net	11,819		11,819		7,633
Depreciation expense	700	$ 600	2,200	$ 1,600
Machinery and equipment
Property and equipment, net:
Total property and equipment, gross	4,365		4,365		3,672
Furniture, fixtures and office equipment
Property and equipment, net:
Total property and equipment, gross	1,551		1,551		809
Computer equipment and software
Property and equipment, net:
Total property and equipment, gross	7,669		7,669		6,846
Leasehold improvements
Property and equipment, net:
Total property and equipment, gross	10,277		10,277		5,560
Construction in process
Property and equipment, net:
Total property and equipment, gross	$ 1,416		$ 1,416		$ 2,021