Earnings Per Share (Schedule Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	May 18, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2019	Aug. 31, 2016
Debt Instrument [Line Items]
Net income (loss) attributable to Green Plains		$ 9,743	$ (8,214)	$ 3,198	$ (24,659)
Weighted-average shares outstanding - basic		45,425	34,603	41,581	34,634
EPS - basic		$ 0.21	$ (0.24)	$ 0.08	$ (0.71)
Net income (loss) attributable to Green Plains - diluted		$ 11,536	$ (8,214)	$ 3,198	$ (24,659)
Weighted-average shares outstanding - diluted		58,171	34,603	42,675	34,634
EPS - diluted		$ 0.20	$ (0.24)	$ 0.07	$ (0.71)
Anti-dilutive weighted-average convertible debt and stock-based compensation	[1]	1,226	14,074	10,233	13,994
Warrants [Member]
Debt Instrument [Line Items]
Effect of dilutive debt/awards		669		345
Stock-Based Compensation Awards [Member]
Debt Instrument [Line Items]
Effect of dilutive debt/awards		698		749
4.125% Convertible Notes Due 2022 [Member] | Corporate Activities [Member] | Convertible Notes [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		4.125%		4.125%				4.125%		4.125%
4.00% Convertible Notes Due 2024 [Member] | Corporate Activities [Member] | Convertible Notes [Member]
Debt Instrument [Line Items]
Interest and amortization on convertible debt, net of tax effect		$ 577
Effect of dilutive debt/awards		4,106
Interest rate, stated percentage		4.00%		4.00%		4.00%		4.00%	4.00%
2.25% Convertible Notes Due 2027 [Member] | Corporate Activities [Member] | Convertible Notes [Member]
Debt Instrument [Line Items]
Interest and amortization on convertible debt, net of tax effect		$ 1,216
Effect of dilutive debt/awards		7,273
Interest rate, stated percentage		2.25%		2.25%			2.25%

[1] Anti-dilutive effects related to the company’s convertible debt and stock-based compensation awards are excluded from diluted EPS for certain periods presented. For the three months ended June 30, 2021, the company excluded the impact of the 4.125% convertible notes due in 2022, and associated interest and amortization, as inclusion would be anti-dilutive. For the six months ended June 30, 2021, the company excluded the impact of the 4.125% convertible notes due in 2022, 4.00% convertible notes due in 2024 and the 2.25% convertible notes due in 2027, and associated interest and amortization, as inclusion would be anti-dilutive. For the three and six months ended June 30, 2020, all convertible debt and stock-based compensation awards were excluded from diluted EPS as inclusion would be anti-dilutive.