Financial Statement Components - Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 27,847		$ 27,847		$ 17,787
Accumulated depreciation and amortization	(7,901)		(7,901)		(6,778)
Total property and equipment, net	19,946		19,946		11,009
Depreciation and amortization	900	$ 700	1,700	$ 1,300
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	10,000		10,000		7,694
Computer hardware and software
Property, Plant and Equipment [Line Items]
Total property and equipment	2,515		2,515		2,854
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	885		885		869
Vehicles, including demonstration fleet
Property, Plant and Equipment [Line Items]
Total property and equipment	2,473		2,473		2,421
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	850		850		272
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 11,124		$ 11,124		$ 3,677