Consolidated Statements of Changes in (Deficit) Equity (USD $) In Thousands, except Share data	Total	Common Stock	Noncontrolling Interest in subsidiaries	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Deferred Compensation
Beginning balance at Oct. 31, 2008	$ 47,058	$ 7	$ 0	$ 578,337	$ (531,286)	$ 0	$ (90)	$ 90
Beginning balance, shares at Oct. 31, 2008		68,782,446
Sale of common stock, shares		14,450,118
Sale of common stock	50,194	1		50,193
Share based compensation	4,815			4,815
Stock issued under benefit plans, shares		1,151,875
Stock issued under benefit plans	1,307			1,307
Preferred dividends - Series B	(3,208)			(3,208)
Change in fair value of warrants	(148)			(148)
Deferred compensation, shares		3,302
Deferred compensation							37	(37)
Effect of foreign currency translation	(2)					(2)
Net loss attributable to FuelCell Energy, Inc.	(68,674)				(68,674)
Ending balance at Oct. 31, 2009	31,342	8	0	631,296	(599,960)	(2)	(53)	53
Ending balance, shares at Oct. 31, 2009		84,387,741
Sale of common stock, shares		27,600,000
Sale of common stock	32,080	3		32,077
Share based compensation	2,965			2,965
Conversion of Series B preferred stock to common stock, net of original issuance costs, shares		8,510
Conversion of Series B preferred stock to common stock, net of original issuance costs	93			93
Stock issued under benefit plans, shares		969,474
Stock issued under benefit plans	721			721
Preferred dividends - Series B	(3,201)			(3,201)
Noncontrolling interest in subsidiaries	(663)		(663)
Effect of foreign currency translation	13					13
Net loss attributable to FuelCell Energy, Inc.	(55,663)				(55,663)
Ending balance at Oct. 31, 2010	7,687	11	(663)	663,951	(655,623)	11	(53)	53
Ending balance, shares at Oct. 31, 2010	112,965,725	112,965,725
Sale of common stock, shares		24,064,924
Sale of common stock	32,864	2		32,862
Share based compensation	2,577			2,577
Stock issued under benefit plans, shares		1,369,848
Stock issued under benefit plans	654			654
Preferred dividends - Series B	(3,200)			(3,200)
FuelCell Ltd. (adjustment from Series 1 modification)	(8,987)			(8,987)
Noncontrolling interest in subsidiaries	(261)		(261)
Effect of foreign currency translation	4					4
Net loss attributable to FuelCell Energy, Inc.	(45,713)				(45,713)
Ending balance at Oct. 31, 2011	$ (14,375)	$ 13	$ (924)	$ 687,857	$ (701,336)	$ 15	$ (53)	$ 53
Ending balance, shares at Oct. 31, 2011	138,400,497	138,400,497