EMPLOYEE BENEFIT PLANS (Details) - USD ($)	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
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	$ 73,000	$ 63,000	$ 57,000
Heron Lake Bio-energy LLC [Member]
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	$ 90,000	$ 85,000	$ 81,000