Nature of Business and Basis of Presentation - Additional Information (Details) $ in Thousands		3 Months Ended		12 Months Ended	19 Months Ended
	Oct. 31, 2023 USD ($)	Jan. 31, 2024 USD ($) MW shares	Oct. 31, 2023 USD ($) Plant MW	Oct. 31, 2023 USD ($)	Jan. 31, 2024 USD ($) shares	Jan. 31, 2023 USD ($)
Nature of Business and Basis of Presentation
Cash and cash equivalents, unrestricted	$ 249,952	$ 297,466	$ 249,952	$ 249,952	$ 297,466	$ 315,168
Investments - short-term	103,760		103,760	103,760
US Treasury Securities
Nature of Business and Basis of Presentation
Investments - short-term	103,800	0	$ 103,800	103,800	$ 0
Tax equity financing transactions with Franklin Park
Nature of Business and Basis of Presentation
Closing costs				1,800
Number of Fuel Cell Power Plants, Tax Equity Financing Transaction | Plant			2
Tax Equity Financing Commitment	30,200		$ 30,200	$ 30,200
Tax equity financing transaction, commitment amount received	$ 9,100	$ 21,100
Common Stock | 2022 Open Market Sale Agreement | Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canacord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC
Nature of Business and Basis of Presentation
Shares sold during the period | shares		0			62,800,000
Derby Project 14.0 Mega Watt
Nature of Business and Basis of Presentation
Capacity of plant | MW		14.0
Derby Project 14.0 Mega Watt | Tax equity financing transactions with Franklin Park
Nature of Business and Basis of Presentation
Capacity of plant | MW			14.0
Derby Project 2.8 Mega Watt
Nature of Business and Basis of Presentation
Capacity of plant | MW		2.8
Derby Project 2.8 Mega Watt | Tax equity financing transactions with Franklin Park
Nature of Business and Basis of Presentation
Capacity of plant | MW			2.8
Groton Project
Nature of Business and Basis of Presentation
Capacity of plant | MW		7.4
Tax equity financing transaction, commitment amount received		$ 4,000