Document and Entity Information - shares	9 Months Ended
	Jul. 31, 2016	Sep. 06, 2016
Document and Entity Information
Entity Registrant Name	FUELCELL ENERGY INC
Entity Central Index Key	0000886128
Document Type	10-Q
Document Period End Date	Jul. 31, 2016
Amendment Flag	false
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--10-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		33,540,364