Financial Statement Components - Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 23,956		$ 17,787
Accumulated depreciation and amortization	(7,519)		(6,778)
Total property and equipment, net	16,437		11,009
Depreciation and amortization	700	$ 700
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	8,286		7,694
Computer hardware and software
Property, Plant and Equipment [Line Items]
Total property and equipment	2,871		2,854
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	885		869
Vehicles, including demonstration fleet
Property, Plant and Equipment [Line Items]
Total property and equipment	2,631		2,421
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	829		272
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 8,454		$ 3,677