Document and Entity Information (USD $)	12 Months Ended
	Oct. 31, 2014	Dec. 31, 2014	Apr. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	FUELCELL ENERGY INC
Entity Central Index Key	0000886128
Document Type	10-K
Document Period End Date	Oct. 31, 2014
Amendment Flag	false
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--10-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		291,130,611
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 502,494,634
Share Price			$ 2.27