Annual report pursuant to Section 13 and 15(d)

Cover Page

Cover Page - USD ($)
12 Months Ended
Dec. 31, 2020
Jan. 31, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-35397    
Entity Registrant Name RENEWABLE ENERGY GROUP, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 26-4785427    
Entity Address, Address Line One 416 South Bell Avenue    
Entity Address, City or Town Ames    
Entity Address, State or Province IA    
Entity Address, Postal Zip Code 50010    
City Area Code 515    
Local Phone Number 239-8000    
Title of 12(b) Security Common Stock, par value $.0001 per share    
Trading Symbol REGI    
Security Exchange Name NASDAQ    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   39,334,839  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Public Float     $ 790,373,860
Documents Incorporated by Reference All or a portion of Items 10 through 14 in Part III of this Form 10-K are incorporated by reference to the Registrant’s definitive proxy statement on Schedule 14A, which will be filed within 120 days after the close of the fiscal year covered by this report on Form 10-K, or if the Registrant’s Schedule 14A is not filed within such period, will be included in an amendment to this Report on Form 10-K which will be filed within such 120 day period.    
Entity Central Index Key 0001463258    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Amendment Flag false