Document and Entity Information - USD ($)	12 Months Ended
	Oct. 31, 2016	Jan. 03, 2017	Apr. 29, 2016
Document Information [Line Items]
Entity Registrant Name	FUELCELL ENERGY INC
Entity Central Index Key	0000886128
Document Type	10-K
Document Period End Date	Oct. 31, 2016
Amendment Flag	false
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--10-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		40,266,946
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 156,420,510
Share Price			$ 5.96