Debt (Schedule Of Aggregate Future Payments Necessary to Discontinue Free Cash Flow Payments) (Details) (Ethanol Production Segment [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Green Plains Bluffton [Member]
Debt Instrument [Line Items]
Aggregate of future payments necessary to discontinue free cash flow payments	$ 15.0
Green Plains Central City And Green Plains Ord Combined [Member]
Debt Instrument [Line Items]
Aggregate of future payments necessary to discontinue free cash flow payments	16.0
Green Plains Obion [Member]
Debt Instrument [Line Items]
Aggregate of future payments necessary to discontinue free cash flow payments	10.1
Green Plains Superior [Member]
Debt Instrument [Line Items]
Aggregate of future payments necessary to discontinue free cash flow payments	$ 10.0