Basis Of Presentation And Description Of Business And Summary Of Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2016
Basis Of Presentation, Description Of Business And Summary Of Significant Accounting Policies [Abstract]
Consolidated Financial Statements	Consolidated Financial Statements The consolidated financial statements include the company’s accounts and all significant intercompany balances and transactions are eliminated. Unconsolidated entities are included in the financial statements on an equity basis. Interim period results are not necessarily indicative of the results to be expected for the entire year. Effective April 1, 2016, the company increased its ownership of BioProcess Algae, a joint venture formed in 2008, to 82.8% and consolidated BioProcess Algae in its consolidated financial statements beginning on that date. The accompanying unaudited consolidated financial statements are prepared in accordance with GAAP for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Because they do not include all of the information and footnotes required by GAAP, the consolidated financial statements should be read in conjunction with the company’s annual report on Form 10-K for the year ended December 31, 2015. The unaudited financial information reflects adjustments which are, in the opinion of management, necessary for a fair presentation of results of operations, financial position and cash flows for the periods presented. The adjustments are normal and recurring in nature, unless otherwise noted.
Reclassifications	Reclassifications Certain prior year amounts were reclassified to conform to the current year presentation. These reclassifications did not affect total revenues, costs and expenses, net income or stockholders’ equity.
Use Of Estimates In The Preparation Of Consolidated Financial Statements	Use of Estimates in the Preparation of Consolidated Financial Statements The preparation of the consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The company bases its estimates on historical experience and assumptions it believes are proper and reasonable under the circumstances and regularly evaluates the appropriateness of its estimates and assumptions. Actual results could differ from those estimates. Key accounting policies, including but not limited to those relating to revenue recognition, depreciation of property and equipment, impairment of long-lived assets and goodwill, derivative financial instruments, and accounting for income taxes, are impacted significantly by judgments, assumptions and estimates used in the preparation of the consolidated financial statements.
Description Of Business	Description of Business Green Plains is the third largest ethanol producer in North America. The company operates within four business segments: (1) ethanol production, which includes the production of ethanol, distillers grains and corn oil, (2) agribusiness, which includes grain handling and storage and cattle feedlot operations, (3) marketing and distribution, which includes marketing and merchant trading for company-produced and third-party ethanol, distillers grains, corn oil, natural gas and other commodities, and (4) partnership, which includes fuel storage and transportation services. The company is also a partner in a joint venture focused on developing technology to grow and harvest algae in commercially viable quantities.
Revenue Recognition	Revenue Recognition The company recognizes revenue when the following criteria are satisfied: persuasive evidence that an arrangement exists, title of product and risk of loss are transferred to the customer, price is fixed and determinable and collectability is reasonably assured. Sales of ethanol, distillers grains, corn oil, natural gas and other commodities by the company’s marketing business are recognized when title of product and risk of loss are transferred to an external customer. Revenues related to marketing for third parties are presented on a gross basis when the company takes title of the product and assumes risk of loss. Unearned revenue is recorded for goods in transit when the company has received payment but the title has not yet been transferred to the customer. Revenues for receiving, storing, transferring and transporting ethanol and other fuels are recognized when the product is delivered to the customer. The company routinely enters into fixed-price, physical-delivery energy commodity purchase and sale agreements. At times, the company settles these transactions by transferring its obligations to other counterparties rather than delivering the physical commodity. These transactions are reported net as a component of revenues. Revenues also include realized gains and losses on related derivative financial instruments, ineffectiveness on cash flow hedges and reclassifications of realized gains and losses on effective cash flow hedges from accumulated other comprehensive income or loss. Sales of agricultural commodities, including cattle, are recognized when title of product and risk of loss are transferred to the customer, which depends on the agreed upon terms. The sales terms provide passage of title when shipment is made or the commodity is delivered. Revenues related to grain merchandising are presented gross and include shipping and handling, which is also a component of cost of goods sold. Revenues from grain storage are recognized when services are rendered. A substantial portion of the partnership revenues are derived from fixed-fee commercial agreements for storage, terminal or transportation services. The partnership recognizes revenue when there is evidence an arrangement exists; risk of loss and title transfer to the customer; the price is fixed or determinable; and collectability is reasonably assured. Revenues from base storage, terminal or transportation services are recognized once these services are performed, which occurs when the product is delivered to the customer.
Cost Of Goods Sold	Cost of Goods Sold Cost of goods sold includes direct labor, materials and plant overhead costs. Direct labor includes all compensation and related benefits of non-management personnel involved in ethanol plant and cattle feedlot operations. Grain purchasing and receiving costs, excluding labor costs for grain buyers and scale operators, are also included in cost of goods sold. Materials include the cost of corn feedstock, denaturant, process chemicals, cattle and veterinary supplies. Corn feedstock costs include unrealized gains and losses on related derivative financial instruments not designated as cash flow hedges, inbound freight charges, inspection costs and transfer costs as well as realized gains and losses on related derivative financial instruments, ineffectiveness on cash flow hedges and reclassifications of realized gains and losses on effective cash flow hedges from accumulated other comprehensive income or loss. Plant overhead consists primarily of plant and feedlot utilities, repairs and maintenance, yard expenses and outbound freight charges. Shipping costs incurred by the company, including railcar costs, are also reflected in cost of goods sold. The company uses exchange-traded futures and options contracts to minimize the effect of price changes on the agribusiness segment’s grain and cattle inventories and forward purchase and sales contracts. Exchange-traded futures and options contracts are valued at quoted market prices and settled predominantly in cash. The company is exposed to loss when counterparties default on forward purchase and sale contracts. Grain inventories held for sale and forward purchase and sale contracts are valued at market prices when available or other market quotes adjusted for differences, primarily in transportation, between the exchange-traded market and local market where the terms of the contract is based. Changes in the fair value of grain inventories held for sale, forward purchase and sale contracts, and exchange-traded futures and options contracts are recognized as a component of cost of goods sold.
Operations and Maintenance Expenses	Operations and Maintenance Expenses In the partnership segment, transportation expenses represent the primary component of operations and maintenance expenses. Transportation expenses includes railcar leases, freight and shipping of the company’s ethanol and co-products, as well as costs incurred storing ethanol at destination terminals.
Derivative Financial Instruments	Derivative Financial Instruments The company uses various derivative financial instruments, including exchange-traded futures and exchange-traded and over-the-counter options contracts, to minimize risk and the effect of price changes related to corn, ethanol, cattle and natural gas. The company monitors and manages this exposure as part of its overall risk management policy to reduce the adverse effect market volatility may have on its operating results. The company may hedge these commodities as one way to mitigate risk, however, there may be situations when the hedging activities themselves result in losses. By using derivatives to hedge exposures to changes in commodity prices, the company is exposed to credit and market risk. The company’s exposure to credit risk includes the counterparty’s failure to fulfill its performance obligations under the terms of the derivative contract. The company minimizes credit risk by entering into transactions with high quality counterparties, limiting the amount of financial exposure it has with each counterparty and monitoring their financial condition. Market risk is the risk that the value of the financial instrument might be adversely affected by a change in commodity prices or interest rates. The company manages market risk by incorporating parameters to monitor exposure within its risk management strategy which limits the types of derivative instruments and strategies the company can use and the degree of market risk it can take using derivative instruments. The company evaluates its physical delivery contracts to determine if they qualify for normal purchase or sale exemptions which are expected to be used or sold over a reasonable period in the normal course of business. Contracts that do not meet the normal purchase or sale criteria are recorded at fair value. Changes in fair value are recorded in operating income unless the contracts qualify for, and the company elects to use, hedge accounting treatment. Certain qualifying derivatives related to the ethanol production and agribusiness segments are designated as cash flow hedges. The company evaluates the derivative instrument to ascertain its effectiveness prior to entering into cash flow hedges. Ineffectiveness is recognized in current period results, while other unrealized gains and losses are reflected in accumulated other comprehensive income until the gain or loss from the underlying hedged transaction is realized. When it becomes probable a forecasted transaction will not occur, the cash flow hedge treatment is discontinued, which affects earnings. These derivative financial instruments are recognized in current assets or other current liabilities at fair value. At times, the company hedges its exposure to changes in the value of inventories and designates qualifying derivatives as fair value hedges. The carrying amount of the hedged inventory is adjusted in current period results for changes in fair value. Ineffectiveness is recognized in current period results to the extent the change in fair value of the inventory is not offset by the change in fair value of the derivative.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Effective January 1, 2016, the company adopted the amended guidance in ASC Topic 835-30, Interest - Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a deduction from the carrying amount of the debt, consistent with debt discounts. The amended guidance has been applied on a retrospective basis, and the balance sheet of each individual period presented has been adjusted to reflect the period-specific effects of the new guidance. Effective January 1, 2017, the company will adopt the amended guidance in ASC 718, Compensation – Stock Compensation, which requires all income tax effects of awards to be recognized in the income statement when the awards vest or settle. The amended guidance also will allow an employer to repurchase more of an employee’s shares than it can currently for tax withholding purposes without triggering liability accounting and make a policy election to account for forfeitures as they occur. Early application is permitted. The company is currently evaluating the impact the adoption of the amended guidance will have on the consolidated financial statements and related disclosures. Effective January 1, 2017, the company will adopt the amended guidance in ASC 330, Inventory: Simplifying the Measurement of Inventory, which requires inventory to be measured at lower of cost or net realizable value. Net realizable value is the estimated selling prices during the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The amended guidance will be applied prospectively. Effective January 1, 2018, the company will adopt the amended guidance in ASC 606, Revenue from Contracts with Customers, which requires revenue recognition to reflect the transfer of promised goods or services to customers. The updated standard permits either the retrospective or cumulative effect transition method. Early application beginning January 1, 2017, is permitted. The company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements and related disclosures. Effective January 1, 2019, the company will adopt the amended guidance in ASC 842, Leases, which aims to make leasing activities more transparent and comparable and requires substantially all leases to be recognized by lessees on their balance sheet as a right-of-use asset and corresponding lease liability, including leases currently accounted for as operating leases. Early application is permitted. The company is currently evaluating the impact the adoption of the amended guidance will have on the consolidated financial statements and related disclosures.