EMPLOYEE BENEFIT PLANS (Details) - USD ($)	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Granite Falls Energy, LLC Excluding Heron Lake BioEnergy, LLC
Defined Contribution Plan Disclosure [Line Items]
Employer match (as a percent)	50.00%
Percentage of employee's salary (as a percent)	3.00%
Employer contribution	$ 67,000	$ 72,000	$ 73,000
Heron Lake Bio-energy LLC
Defined Contribution Plan Disclosure [Line Items]
Employer match (as a percent)	50.00%
Percentage of employee's salary (as a percent)	4.00%
Employer contribution	$ 92,000	$ 98,000	$ 90,000