Summary of Significant Accounting Policies	6 Months Ended
Apr. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Account Policies	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Business Granite Falls Energy, LLC (“GFE”) is a Minnesota limited liability company currently producing fuel-grade ethanol, distillers' grains, and crude corn oil near Granite Falls, Minnesota and sells these products, pursuant to marketing agreements, throughout the continental United States and on the international market. GFE's plant has an approximate annual production capacity of 60 million gallons, but is currently permitted to produce up to 70 million gallons of undenatured ethanol on a twelve month rolling sum basis. Additionally, GFE owns a majority interest in Heron Lake BioEnergy, LLC (“HLBE”). HLBE is a Minnesota limited liability company currently producing fuel-grade ethanol, distillers' grains, and crude corn oil near Heron Lake, Minnesota and sells these products, pursuant to marketing agreements, throughout the continental United States. HLBE's plant has an approximate annual production capacity of 60 million gallons, but is permitted to produce approximately 72.3 million gallons of undenatured ethanol on a twelve month rolling sum basis. HLBE owns a majority interest in Agrinatural Gas, LLC (“Agrinatural”), which operates a natural gas pipeline that provides natural gas to HLBE's ethanol production facility and other customers. All references to “we”, “us”, “our”, and the “Company” collectively refer to GFE and its wholly-owned and majority-owned subsidiaries. Basis of Presentation and Principles of Consolidation The condensed consolidated unaudited financial statements as of April 30, 2017, consolidate the operating results and financial position of GFE, and its approximately 50.7% owned subsidiary, HLBE (through GFE's 100% ownership of Project Viking, LLC). Given the Company’s control over the operations of HLBE and its majority voting interest, the Company consolidates the condensed consolidated unaudited financial statements of HLBE with GFE's condensed consolidated unaudited financial statements. The remaining 49.3% ownership of HLBE is included in the condensed consolidated unaudited financial statements as a non-controlling interest. HLBE, through its wholly owned subsidiary, HLBE Pipeline Company, LLC, owns approximately 73% of Agrinatural. Given HLBE’s control over the operations of Agrinatural and its majority voting interest, HLBE consolidates the financial statements of Agrinatural with its consolidated unaudited financial statements, with the equity and earnings attributed to the remaining approximately 27% noncontrolling interest. All significant intercompany balances and transactions are eliminated in consolidation. The accompanying condensed consolidated unaudited financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted as permitted by such rules and regulations. These financial statements and related notes should be read in conjunction with the financial statements and notes thereto included in the Company’s audited consolidated financial statements for the year ended October 31, 2016, contained in the Company’s annual report on Form 10-K. In the opinion of management, the condensed consolidated unaudited financial statements reflect all adjustments consisting of normal recurring accruals that we consider necessary to present fairly the Company’s results of operations, financial position and cash flows. The results reported in these condensed consolidated unaudited financial statements should not be regarded as necessarily indicative of results that may be expected for any other fiscal period or for the fiscal year. Reportable Operating Segments Accounting Standards Codification (“ASC”) 280, “Segment Reporting,” establishes the standards for reporting information about segments in financial statements. Operating segments are defined as components of an enterprise for which separate financial information is available that is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Therefore, in applying the criteria set forth in ASC 280, the Company determined that based on the nature of the products and production process and the expected financial results, the Company’s operations at GFE’s ethanol plant and HLBE’s plant, including the production and sale of ethanol and its co-products, are aggregated into one reporting segment. Additionally, the Company also realizes relatively immaterial revenue from natural gas pipeline operations at Agrinatural, HLBE’s majority owned subsidiary. Before and after accounting for intercompany eliminations, these revenues from Agrinatural’s represent less than less than 1% of our consolidated revenues and have little to no impact on the overall performance of the Company. Therefore, the Company does not separately review Agrinatural’s revenues, cost of sales or other operating performance information. Rather, the Company reviews Agrinatural’s natural gas pipeline financial data on a consolidated basis with the Company’s ethanol production operating segment. The Company believes that the presentation of separate operating performance information for Agrinatural’s natural gas pipeline operations would not provide meaningful information to a reader of the Company’s consolidated financial statements and would not achieve the basic principles and objectives of ASC 280. Accounting Estimates Management uses estimates and assumptions in preparing these condensed consolidated unaudited financial statements in accordance with generally accepted accounting principles in the United States of America. Those estimates and assumptions affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported revenues and expenses. The Company uses estimates and assumptions in accounting for the following significant matters, among others: economic lives of property and equipment, valuation of commodity derivatives, inventory, and inventory purchase and sale commitments, and the assumptions used in the impairment analysis of long-lived assets, which includes goodwill. Actual results may differ from previously estimated amounts, and such differences may be material to our condensed consolidated unaudited financial statements. The Company periodically reviews estimates and assumptions, and the effects of revisions are reflected in the period in which the revision is made. Revenue Recognition The Company generally sells ethanol and related products pursuant to marketing agreements. Revenues from the production of ethanol and the related products are recorded when the customer has taken title and assumed the risks and rewards of ownership, prices are fixed or determinable and collectability is reasonably assured. Ethanol and related products are generally shipped free on board (FOB) shipping point. The Company believes there are no ethanol sales, during any given month, which should be considered contingent and recorded as deferred revenue. In accordance with the Company's agreements for the marketing and sale of ethanol and related products, marketing fees and commissions due to the marketers are deducted from the gross sales price as earned. These fees and commissions are recorded net of revenues, as they do not provide an identifiable benefit that is sufficiently separable from the sale of ethanol and related products. Shipping costs paid by the Company to the marketer in the sale of ethanol are not specifically identifiable and, as a result, are recorded based on the net selling price reported to the Company from the marketer. Shipping costs incurred by the Company in the sale of distillers' grains and corn oil are included in cost of goods sold. Agrinatural recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the fee for the arrangement is fixed or determinable and collectability is reasonably assured. Inventory Inventory is stated at the lower of cost or net realizable value. Cost for all inventories is determined using the first in first out method (“FIFO”). Net realizable value is the estimated selling prices in the ordinary course of business less reasonably predictable costs of completion, disposal, and transportation. Inventory consists of raw materials, work in process, finished goods, and spare parts. Corn is the primary raw material along with other raw materials. Finished goods consist of ethanol, distillers' grains, and corn oil. Derivative Instruments From time to time the Company enters into derivative transactions to hedge its exposures to commodity price fluctuations. The Company is required to record these derivatives on the balance sheets at fair value. In order for a derivative to qualify as a hedge, specific criteria must be met and appropriate documentation maintained. Gains and losses from derivatives that do not qualify as hedges, or are undesignated, must be recognized immediately in earnings. If the derivative does qualify as a hedge, depending on the nature of the hedge, changes in the fair value of the derivative will be either offset against the change in fair value of the hedged assets, liabilities, or firm commitments through earnings or recognized in other comprehensive income until the hedged item is recognized in earnings. Changes in the fair value of undesignated derivatives are recorded in earnings. Additionally, the Company is required to evaluate its contracts to determine whether the contracts are derivatives. Certain contracts that literally meet the definition of a derivative may be exempted as “normal purchases or normal sales”. Normal purchases and normal sales are contracts that provide for the purchase or sale of something other than a financial instrument or derivative instrument that will be delivered in quantities expected to be used or sold over a reasonable period in the normal course of business. Contracts that meet the requirements of normal purchases or sales are documented as normal and exempted from accounting and reporting requirements, and therefore, are not marked to market in our condensed consolidated unaudited financial statements. In order to reduce the risks caused by market fluctuations, the Company occasionally hedges its anticipated corn, natural gas, and denaturant purchases and ethanol sales by entering into options and futures contracts. These contracts are used with the intention to fix the purchase price of anticipated requirements for corn in the Company's ethanol production activities and the related sales price of ethanol. The fair value of these contracts is based on quoted prices in active exchange-traded or over-the-counter market conditions. Although the Company believes its commodity derivative positions are economic hedges, none have been formally designated as a hedge for accounting purposes and derivative positions are recorded on the balance sheet at their fair market value, with changes in fair value recognized in current period earnings or losses. The Company does not enter into financial instruments for trading or speculative purposes. The Company has adopted authoritative guidance related to “Derivatives and Hedging,” and has included the required enhanced quantitative and qualitative disclosure about objectives and strategies for using derivatives, quantitative disclosures about fair value amounts of gains and losses from derivative instruments, and disclosures about credit-risk-related contingent features in derivative agreements. See further discussion in Note 4. Investment On November 1, 2016, GFE subscribed to purchase 1,500 capital units of Ringneck Energy & Feed, LLC (“Ringneck”) at a price of $5,000 per unit for a total of $7,500,000. GFE paid a down payment of $750,000 in connection with the subscription, and signed a promissory note for $6,750,000 for the remaining balance of the subscription. If Ringneck accepts GFE’s subscription, GFE will be required to pay Ringneck the entire amount due under the promissory note within 20 days of receiving notice from Ringneck that it is due. If GFE fails to pay the entire amount due, GFE will be charged 12% interest per year, and Ringneck may seek legal action to force GFE to pay. If Ringneck does not meet certain conditions of its offering or rejects GFE’s subscription, GFE expects that its promissory note will be cancelled and our down payment will be refunded to us. Ringneck is a South Dakota limited liability company that intends to build an 80 million gallon per year ethanol manufacturing plant in outside of Onida, South Dakota in Sully County. If Ringneck accepts our subscription, our investment is sufficient to secure the Company the right to appoint one director to the board of directors of Ringneck. The investment is accounted for by the equity method, under which the Company’s share of the net income of the investee is recognized as income in the Company’s Consolidated Statement of Operations and added to the investment account, and distributions received from the affiliates are treated as a reduction of the investment.

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Nature of Business

Granite Falls Energy, LLC (“GFE”) is a Minnesota limited liability company currently producing fuel-grade ethanol, distillers' grains, and crude corn oil near Granite Falls, Minnesota and sells these products, pursuant to marketing agreements, throughout the continental United States and on the international market. GFE's plant has an approximate annual production capacity of 60 million gallons, but is currently permitted to produce up to 70 million gallons of undenatured ethanol on a twelve month rolling sum basis.

Additionally, GFE owns a majority interest in Heron Lake BioEnergy, LLC (“HLBE”). HLBE is a Minnesota limited liability company currently producing fuel-grade ethanol, distillers' grains, and crude corn oil near Heron Lake, Minnesota and sells these products, pursuant to marketing agreements, throughout the continental United States. HLBE's plant has an approximate annual production capacity of 60 million gallons, but is permitted to produce approximately 72.3 million gallons of undenatured ethanol on a twelve month rolling sum basis. HLBE owns a majority interest in Agrinatural Gas, LLC (“Agrinatural”), which operates a natural gas pipeline that provides natural gas to HLBE's ethanol production facility and other customers.

All references to “we”, “us”, “our”, and the “Company” collectively refer to GFE and its wholly-owned and majority-owned subsidiaries.

Basis of Presentation and Principles of Consolidation

The condensed consolidated unaudited financial statements as of April 30, 2017, consolidate the operating results and financial position of GFE, and its approximately 50.7% owned subsidiary, HLBE (through GFE's 100% ownership of Project Viking, LLC). Given the Company’s control over the operations of HLBE and its majority voting interest, the Company consolidates the condensed consolidated unaudited financial statements of HLBE with GFE's condensed consolidated unaudited financial statements. The remaining 49.3% ownership of HLBE is included in the condensed consolidated unaudited financial statements as a non-controlling interest. HLBE, through its wholly owned subsidiary, HLBE Pipeline Company, LLC, owns approximately 73% of Agrinatural. Given HLBE’s control over the operations of Agrinatural and its majority voting interest, HLBE consolidates the financial statements of Agrinatural with its consolidated unaudited financial statements, with the equity and earnings attributed to the remaining approximately 27% noncontrolling interest. All significant intercompany balances and transactions are eliminated in consolidation.

The accompanying condensed consolidated unaudited financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted as permitted by such rules and regulations. These financial statements and related notes should be read in conjunction with the financial statements and notes thereto included in the Company’s audited consolidated financial statements for the year ended October 31, 2016, contained in the Company’s annual report on Form 10-K.

In the opinion of management, the condensed consolidated unaudited financial statements reflect all adjustments consisting of normal recurring accruals that we consider necessary to present fairly the Company’s results of operations, financial position and cash flows. The results reported in these condensed consolidated unaudited financial statements should not be regarded as necessarily indicative of results that may be expected for any other fiscal period or for the fiscal year.

Reportable Operating Segments

Accounting Standards Codification (“ASC”) 280, “Segment Reporting,” establishes the standards for reporting information about segments in financial statements. Operating segments are defined as components of an enterprise for which separate financial information is available that is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. Therefore, in applying the criteria set forth in ASC 280, the Company determined that based on the nature of the products and production process and the expected financial results, the Company’s operations at GFE’s ethanol plant and HLBE’s plant, including the production and sale of ethanol and its co-products, are aggregated into one reporting segment.

Additionally, the Company also realizes relatively immaterial revenue from natural gas pipeline operations at Agrinatural, HLBE’s majority owned subsidiary. Before and after accounting for intercompany eliminations, these revenues from Agrinatural’s represent less than less than 1% of our consolidated revenues and have little to no impact on the overall performance of the Company. Therefore, the Company does not separately review Agrinatural’s revenues, cost of sales or other operating performance information. Rather, the Company reviews Agrinatural’s natural gas pipeline financial data on a consolidated basis with the Company’s ethanol production operating segment. The Company believes that the presentation of separate operating performance information for Agrinatural’s natural gas pipeline operations would not provide meaningful information to a reader of the Company’s consolidated financial statements and would not achieve the basic principles and objectives of ASC 280.

Accounting Estimates

Management uses estimates and assumptions in preparing these condensed consolidated unaudited financial statements in accordance with generally accepted accounting principles in the United States of America. Those estimates and assumptions affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported revenues and expenses. The Company uses estimates and assumptions in accounting for the following significant matters, among others: economic lives of property and equipment, valuation of commodity derivatives, inventory, and inventory purchase and sale commitments, and the assumptions used in the impairment analysis of long-lived assets, which includes goodwill. Actual results may differ from previously estimated amounts, and such differences may be material to our condensed consolidated unaudited financial statements. The Company periodically reviews estimates and assumptions, and the effects of revisions are reflected in the period in which the revision is made.

Revenue Recognition

The Company generally sells ethanol and related products pursuant to marketing agreements. Revenues from the production of ethanol and the related products are recorded when the customer has taken title and assumed the risks and rewards of ownership, prices are fixed or determinable and collectability is reasonably assured. Ethanol and related products are generally shipped free on board (FOB) shipping point. The Company believes there are no ethanol sales, during any given month, which should be considered contingent and recorded as deferred revenue.

In accordance with the Company's agreements for the marketing and sale of ethanol and related products, marketing fees and commissions due to the marketers are deducted from the gross sales price as earned. These fees and commissions are recorded net of revenues, as they do not provide an identifiable benefit that is sufficiently separable from the sale of ethanol and related products. Shipping costs paid by the Company to the marketer in the sale of ethanol are not specifically identifiable and, as a result, are recorded based on the net selling price reported to the Company from the marketer. Shipping costs incurred by the Company in the sale of distillers' grains and corn oil are included in cost of goods sold.

Agrinatural recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the fee for the arrangement is fixed or determinable and collectability is reasonably assured.

Inventory

Inventory is stated at the lower of cost or net realizable value. Cost for all inventories is determined using the first in first out method (“FIFO”). Net realizable value is the estimated selling prices in the ordinary course of business less reasonably predictable costs of completion, disposal, and transportation. Inventory consists of raw materials, work in process, finished goods, and spare parts. Corn is the primary raw material along with other raw materials. Finished goods consist of ethanol, distillers' grains, and corn oil.

Derivative Instruments

From time to time the Company enters into derivative transactions to hedge its exposures to commodity price fluctuations. The Company is required to record these derivatives on the balance sheets at fair value.

In order for a derivative to qualify as a hedge, specific criteria must be met and appropriate documentation maintained. Gains and losses from derivatives that do not qualify as hedges, or are undesignated, must be recognized immediately in earnings. If the derivative does qualify as a hedge, depending on the nature of the hedge, changes in the fair value of the derivative will be either offset against the change in fair value of the hedged assets, liabilities, or firm commitments through earnings or recognized in other comprehensive income until the hedged item is recognized in earnings. Changes in the fair value of undesignated derivatives are recorded in earnings.

Additionally, the Company is required to evaluate its contracts to determine whether the contracts are derivatives. Certain contracts that literally meet the definition of a derivative may be exempted as “normal purchases or normal sales”. Normal purchases and normal sales are contracts that provide for the purchase or sale of something other than a financial instrument or derivative instrument that will be delivered in quantities expected to be used or sold over a reasonable period in the normal course of business. Contracts that meet the requirements of normal purchases or sales are documented as normal and exempted from accounting and reporting requirements, and therefore, are not marked to market in our condensed consolidated unaudited financial statements.

In order to reduce the risks caused by market fluctuations, the Company occasionally hedges its anticipated corn, natural gas, and denaturant purchases and ethanol sales by entering into options and futures contracts. These contracts are used with the intention to fix the purchase price of anticipated requirements for corn in the Company's ethanol production activities and the related sales price of ethanol. The fair value of these contracts is based on quoted prices in active exchange-traded or over-the-counter market conditions. Although the Company believes its commodity derivative positions are economic hedges, none have been formally designated as a hedge for accounting purposes and derivative positions are recorded on the balance sheet at their fair market value, with changes in fair value recognized in current period earnings or losses. The Company does not enter into financial instruments for trading or speculative purposes.

The Company has adopted authoritative guidance related to “Derivatives and Hedging,” and has included the required enhanced quantitative and qualitative disclosure about objectives and strategies for using derivatives, quantitative disclosures about fair value amounts of gains and losses from derivative instruments, and disclosures about credit-risk-related contingent features in derivative agreements. See further discussion in Note 4.

Investment

On November 1, 2016, GFE subscribed to purchase 1,500 capital units of Ringneck Energy & Feed, LLC (“Ringneck”) at a price of $5,000 per unit for a total of $7,500,000. GFE paid a down payment of $750,000 in connection with the subscription, and signed a promissory note for $6,750,000 for the remaining balance of the subscription. If Ringneck accepts GFE’s subscription, GFE will be required to pay Ringneck the entire amount due under the promissory note within 20 days of receiving notice from Ringneck that it is due. If GFE fails to pay the entire amount due, GFE will be charged 12% interest per year, and Ringneck may seek legal action to force GFE to pay. If Ringneck does not meet certain conditions of its offering or rejects GFE’s subscription, GFE expects that its promissory note will be cancelled and our down payment will be refunded to us.

Ringneck is a South Dakota limited liability company that intends to build an 80 million gallon per year ethanol manufacturing plant in outside of Onida, South Dakota in Sully County. If Ringneck accepts our subscription, our investment is sufficient to secure the Company the right to appoint one director to the board of directors of Ringneck.

The investment is accounted for by the equity method, under which the Company’s share of the net income of the investee is recognized as income in the Company’s Consolidated Statement of Operations and added to the investment account, and distributions received from the affiliates are treated as a reduction of the investment.