XML 10 R1.htm IDEA: XBRL DOCUMENT v3.21.1
Cover Cover
May 06, 2021
May 07, 2020
Cover [Abstract]    
Document Type 8-K  
Entity Registrant Name NRG ENERGY, INC.  
Document Period End Date May 06, 2021  
Entity Central Index Key   0001013871
Amendment Flag   false
Entity Incorporation, State or Country Code DE  
Entity File Number 001-15891  
Entity Tax Identification Number 41-1724239  
Entity Address, Address Line One 804 Carnegie Center  
Entity Address, City or Town Princeton  
Entity Address, State or Province NJ  
Entity Address, Postal Zip Code 08540  
City Area Code 609  
Local Phone Number 524-4500  
Written Communications false  
Soliciting Material false  
Pre-commencement Tender Offer false  
Pre-commencement Issuer Tender Offer false  
Title of 12(b) Security Common Stock, par value $0.01  
Trading Symbol NRG  
Security Exchange Name NYSE  
Entity Emerging Growth Company false