Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Jul. 31, 2012		Jul. 31, 2011		Jul. 31, 2012		Jul. 31, 2011
Revenues (1):
Product sales and revenues	$ 27,569		$ 29,382		$ 79,280		$ 81,815
Research and development contracts	2,124		1,778		5,903		6,032
Total revenues	29,693	[1]	31,160	[1]	85,183	[1]	87,847	[1]
Costs of revenues:
Cost of product sales and revenues	30,321		29,133		80,062		94,652
Cost of research and development contracts	2,110		1,890		5,554		6,244
Total costs of revenues	32,431		31,023		85,616		100,896
Gross profit (loss)	(2,738)		137		(433)		(13,049)
Operating expenses:
Administrative and selling expenses	4,580		3,578		12,346		12,082
Research and development expenses	3,193		3,918		10,932		12,662
Total costs and expenses	7,773		7,496		23,278		24,744
Loss from operations	(10,511)		(7,359)		(23,711)		(37,793)
Interest expense	(544)		(847)		(1,749)		(1,829)
Loss from equity investment	(42)		(94)		(554)		(149)
License fee and royalty income	422		499		1,258		1,287
Other income (expense), net	656		(29)		438		173
Loss before redeemable preferred stock of subsidiary					(24,318)		(38,311)
Accretion of redeemable preferred stock of subsidiary					0		(525)
Loss before benefit (provision) for income taxes	(10,019)		(7,830)		(24,318)		(38,836)
Benefit (provision) for income taxes	9		0		(69)		(9)
Net Loss	(10,010)		(7,830)		(24,387)		(38,845)
Net loss attributable to noncontrolling interest	88		76		230		197
Net loss attributable to FuelCell Energy	(9,922)		(7,754)		(24,157)		(38,648)
Adjustment for Modification of Redeemable Preferred Stock of Subsidiary	0		0		0		8,987
Preferred stock dividends	(800)		(800)		(2,401)		(2,400)
Net loss to common shareholders	$ (10,722)		$ (8,554)		$ (26,558)		$ (50,035)
Loss per share basic and diluted
Net loss per share to common shareholders	$ (0.06)		$ (0.07)		$ (0.17)		$ (0.41)
Basic and diluted weighted average shares outstanding	185,906,834		126,923,550		158,548,998		122,306,465

[1] Includes revenue from a related party. Refer to Concentrations in note 1 to the financial statements.