Revolving Line of Credit Line of Credit (Details) (USD $) | 3 Months Ended | | | | 1 Months Ended | 3 Months Ended | 6 Months Ended | | | | | | | | | | | | 3 Months Ended | | | | | | | | | | | 6 Months Ended | 0 Months Ended |
Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Apr. 30, 2014 | Oct. 31, 2013 | Sep. 30, 2013 | Apr. 30, 2014 | Apr. 30, 2014 | Oct. 31, 2013 | 17-May-13 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Apr. 30, 2014 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Oct. 31, 2013 | Apr. 30, 2014 | Apr. 30, 2013 | Jun. 16, 2014 |
Revolving Operating Loan [Member] | Revolving Term Loan [Member] | Revolving Term Loan [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Agrinatural, LLC [Member] | Agrinatural, LLC [Member] | AgStar [Member] | AgStar [Member] | Federated Electric [Member] | Federated Electric [Member] | SRS [Member] | SRS [Member] | Granite Falls Energy, LLC [Member] | Granite Falls Energy, LLC [Member] | Granite Falls Energy, LLC [Member] | Granite Falls Energy, LLC [Member] | Interest Rate, 6.55% [Member] | Interest Rate, 6.55% [Member] | Savings Account Balance Requirement [Member] | Savings Account Balance Requirement [Member] | Subsequent Event [Member] |
| | | | | | | | Revolving Operating Loan [Member] | Revolving Operating Loan [Member] | Revolving Term Loan [Member] | Revolving Term Loan [Member] | Corn Oil Separation Equipment Loan [Member] | Corn Oil Separation Equipment Loan [Member] | | | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | Shuttlewagon Railcar Mover [Member] | Shuttlewagon Railcar Mover [Member] | Revolving Term Loan [Member] | Revolving Term Loan [Member] | City/County Juristiction [Member] | City/County Juristiction [Member] | Granite Falls Energy, LLC [Member] | Granite Falls Energy, LLC [Member] | Heron Lake Bioenergy [Member] |
| | | | | | | | | | | | | | | | Revolving Term Loan [Member] | Fixed Term Note [Member] | | | | | | | | | Heron Lake Bioenergy [Member] | Heron Lake Bioenergy [Member] | | | |
Debt Instrument [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Instrument, Covenant Description | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | '0 | '0 | ' |
Debt Instrument, Basis Spread on Variable Rate | ' | ' | ' | ' | ' | ' | ' | 5.00% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Amount Outstanding | ' | ' | ' | $0 | $2,513,674 | ' | ' | ' | ' | ' | $17,333,797 | $18,317,800 | $0 | $6,263,158 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $0 | $382,918 | $0 | $2,513,674 | ' | ' | ' | ' | ' |
Convertible Subordinated Debt | ' | ' | ' | ' | ' | 3,700,000 | 4,143,000 | 4,143,000 | 4,143,000 | 1,400,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Subordinated Borrowing, Interest Rate | ' | ' | ' | ' | ' | ' | 7.25% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Long-term Debt | 26,550,215 | 36,472,763 | 5,600,000 | 18,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 378,380 | 640,653 | 300,000 | 300,000 | ' | ' | 256,250 | 293,750 | 1,550,374 | 1,013,132 | ' | ' | ' | ' | 2,588,414 | 2,604,678 | ' | ' | ' |
Long-term Debt, Current Maturities | -7,579,332 | -3,490,808 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Long-Term Debt, less current portion | 18,970,883 | 32,981,955 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Future Reduction, Amount | 2,000,000 | ' | ' | ' | ' | ' | 2,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum | ' | ' | ' | ' | ' | ' | 3.50% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Interest Rate Description | '"One Month LIBOR Index Rate," plus 2.8% and 3.05% | ' | ' | ' | ' | ' | 'LIBOR | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 'LIBOR plus 3.50% but not less than 5% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Letters of Credit Outstanding, Amount | 288,928 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Instrument, Interest Rate, Stated Percentage | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 5.75% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | ' | ' | ' | ' | ' | ' | 0.35% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Remaining Borrowing Capacity | ' | ' | 5,711,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 20,500,000 | 17,400,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Instrument, Amortization Period | ' | ' | ' | ' | ' | ' | ' | '10 years | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Expiration Date | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1-Sep-16 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Excess Cash Flow Payment, Percentage | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 25.00% | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Line of Credit Facility, Excess Cash Flow Payment | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2,000,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Instrument, Convertible, Number of Equity Instruments | ' | ' | ' | ' | ' | ' | ' | 13,810,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Instrument, Convertible, Conversion Price | ' | ' | ' | ' | ' | ' | $0.30 | $0.30 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Debt Conversion, Converted Instrument, Amount | ' | ' | ' | ' | ' | $934,500 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $2,700,000 |
Debt Conversion, Converted Instrument, Shares Issued | ' | ' | ' | ' | ' | 3,115,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 8,857,500 |