Summary of Significant Accounting Policies Narrative (Details) gal in Millions	12 Months Ended
	Oct. 31, 2015 gal
Heron Lake Bioenergy [Member]
Equity Method Investment, Ownership Percentage	50.60%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.40%
Plant production capacity	60.0
Heron Lake Bioenergy [Member] | Maximum [Member]
Plant production capacity	72.3
Agrinatural, LLC [Member]
Equity Method Investment, Ownership Percentage	73.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	27.00%
Granite Falls Energy [Member]
Plant production capacity	60.0
Production (Actual)	70.0
Measurement, Rolling Twelve Months	twelve