Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
Revenues:
Total revenues	$ 25,510	$ 43,104	$ 100,932	$ 91,283
Costs of revenues:
Total costs of revenues	33,725	47,284	110,003	105,668
Gross loss	(8,215)	(4,180)	(9,071)	(14,385)
Operating expenses:
Administrative and selling expenses	17,560	14,158	47,637	64,357
Research and development expenses	15,620	9,659	43,000	22,316
Total costs and expenses	33,180	23,817	90,637	86,673
Loss from operations	(41,395)	(27,997)	(99,708)	(101,058)
Interest expense	(1,912)	(1,622)	(4,926)	(4,757)
Interest income	3,966	932	11,064	1,025
Gain on extinguishment of finance obligations and debt, net	15,337		15,337
Other income, net	403	204	216	61
Loss before provision for income taxes	(23,601)	(28,483)	(78,017)	(104,729)
Provision for income taxes		(494)	(581)	(494)
Net loss	(23,601)	(28,977)	(78,598)	(105,223)
Net income (loss) attributable to noncontrolling interests	678	437	(1,394)	(4,968)
Net loss attributable to FuelCell Energy, Inc.	(24,279)	(29,414)	(77,204)	(100,255)
Series B preferred stock dividends	(800)	(800)	(2,400)	(2,400)
Net loss attributable to common stockholders	$ (25,079)	$ (30,214)	$ (79,604)	$ (102,655)
Loss per share basic and diluted:
Net loss per share attributable to common stockholders, basic	$ (0.06)	$ (0.08)	$ (0.19)	$ (0.27)
Net loss per share attributable to common stockholders, diluted	$ (0.06)	$ (0.08)	$ (0.19)	$ (0.27)
Basic weighted average shares outstanding	415,867,594	387,465,758	409,361,826	375,638,293
Diluted weighted average shares outstanding	415,867,594	387,465,758	409,361,826	375,638,293
Net loss	$ (23,601)	$ (28,977)	$ (78,598)	$ (105,223)
Other comprehensive income (loss):
Foreign currency translation adjustments	(164)	(86)	132	(326)
Total comprehensive loss	(23,765)	(29,063)	(78,466)	(105,549)
Comprehensive income (loss) attributable to noncontrolling interests	678	437	(1,394)	(4,968)
Comprehensive loss attributable to FuelCell Energy, Inc.	(24,443)	(29,500)	(77,072)	(100,581)
Series B Preferred Stock
Operating expenses:
Series B preferred stock dividends	(800)	(800)	(2,400)	(2,400)
Product
Revenues:
Total revenues		18,000	9,095	36,000
Costs of revenues:
Total costs of revenues	2,910	17,919	7,425	39,159
Service
Revenues:
Total revenues	9,841	9,049	49,913	13,855
Costs of revenues:
Total costs of revenues	9,575	7,718	40,633	13,123
Generation
Revenues:
Total revenues	10,982	10,877	28,979	27,423
Costs of revenues:
Total costs of revenues	17,483	18,136	51,166	42,978
Advanced Technologies
Revenues:
Total revenues	4,687	5,178	12,945	14,005
Costs of revenues:
Total costs of revenues	$ 3,757	$ 3,511	$ 10,779	$ 10,408