Derivative Financial Instruments (Schedule Of Gain Or Loss Recognized In Income And Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivative Instruments Not Designated in a Hedging Relationship	$ (1,123)	$ 11,561	$ (2,553)	$ (6,814)
Gains (Losses) Due to Ineffectiveness of Cash Flow Hedges	130	(9)	(70)	(45)
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Net Income	(3,294)	1,450	(3,875)	(1,120)
Gains (Losses) from Fair Value Hedges of Inventory	448	1,218	64	2,748
Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivative Instruments Not Designated in a Hedging Relationship	(1,084)	(9,431)	6,187	(9,597)
Gains (Losses) Due to Ineffectiveness of Cash Flow Hedges	34	14	(5)	(45)
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Net Income	25,254	935	12,029	4,643
Revenue (Effect of Change In Inventory Value) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) from Fair Value Hedges of Inventory	(40)		1,379
Revenue (Effect of Fair Value Hedge) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) from Fair Value Hedges of Inventory	40		(1,379)
Cost of Goods Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) on Derivative Instruments Not Designated in a Hedging Relationship	(39)	20,992	(8,740)	2,783
Gains (Losses) Due to Ineffectiveness of Cash Flow Hedges	96	(23)	(65)
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Net Income	(28,548)	515	(15,904)	(5,763)
Cost of Goods Sold (Effect of Change in Inventory Value) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) from Fair Value Hedges of Inventory	(470)	376	7,712	(1,994)
Cost of Goods Sold (Effect of Fair Value Hedge) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) from Fair Value Hedges of Inventory	$ 918	$ 842	$ (7,648)	$ 4,742

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624177-113959

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1),(2)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

+ Details

Name:	us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=gpre_RevenueEffectOfChangeInInventoryValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=gpre_RevenueEffectOfFairValueHedgeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=gpre_CostOfGoodsSoldEffectOfChangeInInventoryValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=gpre_CostOfGoodsSoldEffectiveFairValueHedgeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: