Quarterly report pursuant to Section 13 or 15(d)

Cover Page

Cover Page - shares
6 Months Ended
Jun. 30, 2020
Jul. 31, 2020
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2020  
Document Transition Report false  
Entity File Number 001-35397  
Entity Registrant Name RENEWABLE ENERGY GROUP, INC.  
Entity Central Index Key 0001463258  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q2  
Amendment Flag false  
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 $0.0001 per share  
Trading Symbol REGI  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   39,292,154