Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2021	Jan. 01, 2021	May 31, 2020	May 29, 2020	May 18, 2020
Summary of Significant Accounting Policies
Operating lease maximum allowed extension percentage	75.00%
Minimum number of days after an invoice is issued when accounts receivable is considered due	30 days
Maximum number of days after an invoice is issued when accounts receivable is considered due	60 days
Allowance for doubtful accounts receivable	$ 39	$ 172
Convertible Debt					$ 120,600
Accumulated deficit	(2,396,903)	(1,946,488)			9,600
Additional paid-in capital	$ 7,070,710	3,446,650			$ 130,200
Existing contracts	5 years
Investment in non-marketable equity securities	$ 5,000	1,000
Stock-Based Compensation
Tax benefit (expense) for stock-based compensation	$ 0	$ 0	$ 0
3.75% Convertible Senior Notes
Summary of Significant Accounting Policies
Interest rate (as a percent)	3.75%	3.75%		3.75%		3.75%	3.75%	3.75%
Fuel
Property, Plant and Equipment
Estimated useful life	10 years
Hydrogen infrastructure
Property, Plant and Equipment
Estimated useful life	20 years
Minimum
Summary of Significant Accounting Policies
Payment terms for fuel cells and its services	30 days
Extension period	5 years
Uptime of the fleet (as a percent)	97.00%
Capitalized commission fees amortization term	5 years
Intangible Assets
Intangible asset useful lives	5 years
Maximum
Summary of Significant Accounting Policies
Payment terms for fuel cells and its services	90 days
Extension period	10 years
Uptime of the fleet (as a percent)	98.00%
Capitalized commission fees amortization term	10 years
Intangible Assets
Intangible asset useful lives	15 years
Leasehold Improvements | Minimum
Property, Plant and Equipment
Estimated useful life	5 years
Leasehold Improvements | Maximum
Property, Plant and Equipment
Estimated useful life	10 years
Software, machinery and equipment | Minimum
Property, Plant and Equipment
Estimated useful life	1 year
Software, machinery and equipment | Maximum
Property, Plant and Equipment
Estimated useful life	30 years