Document and Entity Information - USD ($)	12 Months Ended
	Oct. 31, 2019	Jan. 29, 2020	Apr. 30, 2019
Cover [Abstract]
Document Type	10-K
Document Period End Date	Oct. 31, 2019
Entity Registrant Name	Granite Falls Energy, LLC
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 20,094,000
Entity Common Stock, Shares Outstanding		30,606
Current Fiscal Year End Date	--10-31
Entity Central Index Key	0001181749
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false