Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2022
Revenues:
Total revenues	$ 38,349	$ 16,384	$ 75,422	$ 48,179
Costs of revenues:
Total costs of revenues	44,442	23,694	76,278	58,384
Gross loss	(6,093)	(7,310)	(856)	(10,205)
Operating expenses:
Administrative and selling expenses	15,068	13,234	30,077	50,199
Research and development expenses	14,697	7,673	27,380	12,657
Total costs and expenses	29,765	20,907	57,457	62,856
Loss from operations	(35,858)	(28,217)	(58,313)	(73,061)
Interest expense	(1,502)	(1,707)	(3,014)	(3,135)
Interest income	3,688	84	7,098	94
Other expense, net	(236)	(286)	(187)	(144)
Loss before provision for income taxes	(33,908)	(30,126)	(54,416)	(76,246)
Provision for income taxes	(3)		(581)
Net loss	(33,911)	(30,126)	(54,997)	(76,246)
Net income (loss) attributable to noncontrolling interests	392	91	(2,072)	(5,405)
Net loss attributable to FuelCell Energy, Inc.	(34,303)	(30,217)	(52,925)	(70,841)
Series B preferred stock dividends	(800)	(800)	(1,600)	(1,600)
Net loss attributable to common stockholders	$ (35,103)	$ (31,017)	$ (54,525)	$ (72,441)
Loss per share basic and diluted:
Net loss per share attributable to common stockholders, basic	$ (0.09)	$ (0.08)	$ (0.13)	$ (0.20)
Net loss per share attributable to common stockholders, diluted	$ (0.09)	$ (0.08)	$ (0.13)	$ (0.20)
Basic weighted average shares outstanding	406,316,070	372,615,824	406,055,027	369,626,543
Diluted weighted average shares outstanding	406,316,070	372,615,824	406,055,027	369,626,543
Net loss	$ (33,911)	$ (30,126)	$ (54,997)	$ (76,246)
Other comprehensive income (loss):
Foreign currency translation adjustments	(151)	(149)	296	(240)
Total comprehensive loss	(34,062)	(30,275)	(54,701)	(76,486)
Comprehensive income attributable to noncontrolling interest	392	91	(2,072)	(5,405)
Comprehensive loss attributable to FuelCell Energy, Inc.	(34,454)	(30,366)	(52,629)	(71,081)
Series B Preferred Stock
Operating expenses:
Series B preferred stock dividends	(800)	(800)	(1,600)	(1,600)
Product
Revenues:
Total revenues			9,095	18,000
Costs of revenues:
Total costs of revenues	3,486	3,033	4,515	21,240
Service
Revenues:
Total revenues	26,190	2,639	40,072	4,806
Costs of revenues:
Total costs of revenues	20,113	3,033	31,058	5,405
Generation
Revenues:
Total revenues	8,440	9,050	17,997	16,546
Costs of revenues:
Total costs of revenues	17,081	14,120	33,683	24,842
Advanced Technologies
Revenues:
Total revenues	3,719	4,695	8,258	8,827
Costs of revenues:
Total costs of revenues	$ 3,762	$ 3,508	$ 7,022	$ 6,897