Consolidated Statements of Changes in (Deficit) Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Deferred Compensation [Member]	Noncontrolling Interest In Subsidiaries [Member]
Balance at at Oct. 31, 2010	$ 7,687	$ 11	$ 663,951	$ (655,623)	$ 11	$ (53)	$ 53	$ (663)
Balance at (in shares) at Oct. 31, 2010		112,965,725
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Sale of common stock (in shares)		24,064,924
Sale of common stock	32,864	2	32,862
Common stock issued for acquisition	0
Share based compensation	2,577		2,577
Stock issued under benefit plans (in shares)		1,369,848
Stock issued under benefit plans	654		654
Preferred stock dividends	(3,200)		(3,200)
Noncontrolling interest in subsidiaries	(261)							(261)
Effect of foreign currency translation	4				4
Net loss attributable to FuelCell Energy, Inc.	(45,713)			(45,713)
Adjustment for Modification of Redeemable Preferred Stock of Subsidiary	(8,987)		(8,987)
Balance at at Oct. 31, 2011	(14,375)	13	687,857	(701,336)	15	(53)	53	(924)
Balance at (in shares) at Oct. 31, 2011		138,400,497
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Sale of common stock (in shares)	2,012,506	45,012,306
Sale of common stock	64,003	5	63,998
Share based compensation	2,054		2,054
Stock issued under benefit plans (in shares)		2,443,320
Stock issued under benefit plans	548		548
Preferred stock dividends	(3,201)		(3,201)
Noncontrolling interest in subsidiaries	(411)							(411)
Sale of noncontrolling interest in subsidiary	954							954
Effect of foreign currency translation	51				51
Net loss attributable to FuelCell Energy, Inc.	(35,495)			(35,495)
Adjustment for Modification of Redeemable Preferred Stock of Subsidiary	0
Balance at at Oct. 31, 2012	14,128	18	751,256	(736,831)	66	(53)	53	(381)
Balance at (in shares) at Oct. 31, 2012	185,856,123	185,856,123
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Sale of common stock (in shares)	4,295,800	4,295,800
Sale of common stock	5,548	1	5,547
Common stock issued for acquisition (in shares)	3,526,764
Common stock issued for acquisition	3,563	1	3,562
Share based compensation	2,226		2,226
Stock issued under benefit plans (in shares)		2,631,715
Stock issued under benefit plans	(173)		(173)
Reclass of noncontrolling interest due to liquidation of subsidiaries	0		(562)					562
Preferred stock dividends	(3,200)		(3,200)
Noncontrolling interest in subsidiaries	(961)							(961)
Effect of foreign currency translation	35				35
Net loss attributable to FuelCell Energy, Inc.	(34,358)			(34,358)
Adjustment for Modification of Redeemable Preferred Stock of Subsidiary	0
Balance at at Oct. 31, 2013	$ (13,192)	$ 20	$ 758,656	$ (771,189)	$ 101	$ (53)	$ 53	$ (780)
Balance at (in shares) at Oct. 31, 2013	196,310,402	196,310,402