v3.25.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents $ 1,070 $ 748    
Restricted cash:        
Total cash, cash equivalents, and restricted cash 1,101 921 $ 2,037 $ 1,829
Other current assets        
Restricted cash:        
Restricted cash 31 141    
Other deferred charges and assets        
Restricted cash:        
Restricted cash   31    
Alabama Power        
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents 585 324    
Restricted cash:        
Total cash, cash equivalents, and restricted cash 585 409 687 1,060
Alabama Power | Other current assets        
Restricted cash:        
Restricted cash 0 85    
Alabama Power | Other deferred charges and assets        
Restricted cash:        
Restricted cash   0    
Georgia Power        
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents 97 9    
Restricted cash:        
Total cash, cash equivalents, and restricted cash 118 75 480 33
Georgia Power | Other current assets        
Restricted cash:        
Restricted cash 21 37    
Georgia Power | Other deferred charges and assets        
Restricted cash:        
Restricted cash   29    
Southern Power        
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents 159 124    
Restricted cash:        
Total cash, cash equivalents, and restricted cash 168 144 133 135
Southern Power | Other current assets        
Restricted cash:        
Restricted cash 9 17    
Southern Power | Other deferred charges and assets        
Restricted cash:        
Restricted cash   3    
Southern Power | Proceeds From Issuance Of Solid Waste Disposal Facility Revenue Bonds        
Restricted cash:        
Restricted cash 9 17    
Southern Power | Estimated Construction Completion Costs | Deuel Harvest        
Restricted cash:        
Restricted cash   3    
Southern Company Gas        
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents 43 33    
Restricted cash:        
Total cash, cash equivalents, and restricted cash 44 35 $ 83 $ 48
Southern Company Gas | Other current assets        
Restricted cash:        
Restricted cash $ 1 2    
Southern Company Gas | Other deferred charges and assets        
Restricted cash:        
Restricted cash   $ 0