v3.25.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Impairment and Goodwill and Other Intangible Assets and Liabilities (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Sep. 30, 2024
Dec. 31, 2022
Goodwill [Line Items]    
Goodwill impairment   $ 119
Alabama Power    
Goodwill [Line Items]    
Impairment charges $ 36  
Impairment charges, after tax $ 27