Document And Entity Information - shares
9 Months Ended
Sep. 30, 2019
Nov. 04, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2019  
Document Quarterly Report true  
Document Transition Report false  
Entity Registrant Name Green Plains Inc.  
Entity Central Index Key 0001309402  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   35,955,233
Entity Incorporation, State or Country Code IA  
Entity Interactive Data Current Yes  
Entity Current Reporting Status Yes  
Trading Symbol GPRE  
Security Exchange Name NASDAQ  
Title of 12(b) Security Common Stock, par value $0.001 per share  
Entity Address, Address Line One 1811 Aksarben Drive  
Entity Address, City or Town Omaha  
Entity Address, State or Province NE  
Entity Address, Postal Zip Code 68106  
City Area Code 402  
Local Phone Number 884-8700  
Entity File Number 001-32924  
Entity Shell Company false  
Entity Tax Identification Number 84-1652107