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Revenue Recognition - Additional Information (Details) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 28, 2024 USD ($) item MW	May 31, 2023 USD ($)	Jul. 31, 2024 USD ($) T	Jul. 31, 2023 USD ($)	Jul. 31, 2024 USD ($) T	Jul. 31, 2023 USD ($)	Oct. 31, 2023 USD ($)	Oct. 31, 2022 USD ($)	Mar. 31, 2024 USD ($)	Jan. 31, 2024 USD ($)
Revenue Recognition
Contract asset			$ 50,100		$ 50,100		$ 42,100
Contract asset, long-term			19,900		19,900		25,800
Contract liability			12,600		12,600		3,100
Revenues			$ 23,695	$ 25,510	62,806	$ 100,932
Amount of long-term service agreement	$ 159,600
Toyota Investment Tax Credit Sale
Revenue Recognition
Consideration payable							6,300
Consideration payable, long term							6,000
Sale of investment tax credit							$ 6,300
Hydrogen production and power purchase agreement							20 years
EMTEC Joint Development Agreement
Revenue Recognition
Contract liability										$ 11,600
Revenues		$ 2,500			$ 1,400
Discount on purchase of fuel cell module							$ 2,500
Milestone payment received								$ 5,000
Remaining balance		$ 2,500
Milestone based payments								$ 5,000
Amendment No 5 to EMTEC Joint Development Agreement
Revenue Recognition
Minimum expected annual budget for the anticipated work through the remaining term of agreement									$ 10,000
GGE
Revenue Recognition
Capacity of plant \| MW	58.8
Number of plants \| item	21
Number of cells per plant \| item	2
Number of fuel cells \| item	42
Capacity of fuel cell \| MW	1.4
Long term service agreement term	7 years
GGE \| Fall 2024
Revenue Recognition
Capacity of fuel cell \| MW	1.4
GGE \| Calendar Year 2025
Revenue Recognition
Number of fuel cells \| item	30
Capacity of fuel cell \| MW	1.4
GGE \| First Half Calendar Year 2026
Revenue Recognition
Number of fuel cells \| item	6
Capacity of fuel cell \| MW	1.4
Maximum \| Amendment No 5 to EMTEC Joint Development Agreement
Revenue Recognition
CO2 capture annual basis \| T			250,000		250,000
Service
Revenue Recognition
Revenues			$ 1,411	9,841	$ 4,397	49,913
Generation
Revenue Recognition
Revenues			13,402	10,982	38,013	28,979
Remaining performance obligations			$ 396,400		$ 396,400
Generation \| Maximum
Revenue Recognition
Revenue performance obligation expected timing of satisfaction			20 years		20 years
Generation \| Minimum
Revenue Recognition
Revenue performance obligation expected timing of satisfaction			19 years		19 years
Advanced Technologies
Revenue Recognition
Revenues			$ 8,632	$ 4,687	$ 20,146	12,945
Remaining performance obligations			$ 10,900		$ 10,900
Advanced Technologies \| Maximum
Revenue Recognition
Revenue performance obligation expected timing of satisfaction			2 years		2 years
Product
Revenue Recognition
Revenues			$ 250		$ 250	$ 9,095
Remaining performance obligations			136,700		136,700
Service Agreements \| Service
Revenue Recognition
Remaining performance obligations			$ 178,400		$ 178,400
Service Agreements \| Service \| Maximum
Revenue Recognition
Revenue performance obligation expected timing of satisfaction			15 years		15 years
Service Agreements \| Service \| Minimum
Revenue Recognition
Revenue performance obligation expected timing of satisfaction			3 years		3 years