Debt (Narrative - Agribusiness And Energy Services Segment) (Details)	6 Months Ended
Jun. 30, 2018 USD ($) property	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Short-term notes payable and other borrowings	$ 457,472,000	$ 526,180,000
Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jul. 26, 2019
Additional amounts available under facility, accordion feature	$ 75,000,000
Line of credit, maximum borrowing capacity	125,000,000
Minimum working capital required for compliance	22,000,000
Minimum net worth required for compliance	27,000,000
Annual capital expenditures, maximum	8,000,000
Line of credit, initial borrowings	$ 0
Allowable dividends as percentage of net profit before taxes	50.00%
Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Revolving Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate, basis for effective rate	LIBOR plus 3.00%
Interest rate, basis spread on variable rate, percentage	3.00%
Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Interest rate, basis for effective rate	base rate plus 2.00%
Interest rate, basis spread on variable rate, percentage	2.00%
Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Revolving Credit Facility [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio	1.25
Unused capacity fee, percentage	0.375%
Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Revolving Credit Facility [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 250,000,000
Annual leverage ratio	6.00
Unused capacity fee, percentage	0.50%
Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Seasonal Borrowings [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 50,000,000
Agribusiness And Energy Services [Member] \| Green Plains Trade [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Additional amounts available under facility, accordion feature	70,000,000
Line of credit, maximum borrowing capacity	300,000,000
Annual capital expenditures, maximum	$ 1,500,000
Fixed charge coverage ratio	1.15
Allowable dividends as percentage of net profit before taxes	50.00%
Undrawn availability of revolving credit facility on a pro forma basis	$ 10,000,000
Unused capacity fee, percentage	0.375%
Agribusiness And Energy Services [Member] \| Green Plains Trade [Member] \| Revolving Credit Facility [Member] \| Minimum [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate, basis spread on variable rate, percentage	2.25%
Agribusiness And Energy Services [Member] \| Green Plains Trade [Member] \| Revolving Credit Facility [Member] \| Maximum [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate, basis spread on variable rate, percentage	3.25%
Agribusiness And Energy Services [Member] \| Green Plains Trade [Member] \| Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 285,000,000
Agribusiness And Energy Services [Member] \| Green Plains Trade [Member] \| First-in-last-out (FILO) Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 15,000,000
Collateral Pledged [Member] \| Agribusiness And Energy Services [Member] \| Green Plains Grain [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Number of ethanol plants \| property	17
$20.0 Million Hedge Line [Member] \| Green Plains Commodity Management [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 20,000,000	$ 20,000,000
Short-term notes payable and other borrowings	11,355,000
$20.0 Million Hedge Line [Member] \| Agribusiness And Energy Services [Member] \| Green Plains Commodity Management [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 20,000,000
$20.0 Million Hedge Line [Member] \| Agribusiness And Energy Services [Member] \| Green Plains Commodity Management [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate, basis for effective rate	LIBOR plus 1.75%
Interest rate, basis spread on variable rate, percentage	1.75%

Dividends As Percentage Of Net Profit Before Tax

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- Definition

Annual Capital Expenditures, Maximum

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- Definition

Annual leverage ratio

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No definition available.

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- Definition

Debt Instrument Credit Facility Amounts Available Accordion Feature

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- Definition

Fixed Charge Coverage Ratio

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- Definition

Working capital - current assets less current liabilities

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- Definition

Number Of Ethanol Plants

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- Definition

Undrawn Availability of Revolving Credit Facility On A ProForma Basis

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
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Description of any adjustments made to the stated rate to determine the effective rate.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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-Publisher FASB
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-SubTopic 10
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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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- Definition

The lowest amount of net worth (total assets minus total liabilities) required by secondary market investors or state-imposed regulatory mandates.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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-Publisher FASB
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