v3.25.0.1
REVENUE FROM CONTRACTS WITH CUSTOMERS - Contract Balances (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Revenue [Line Items]    
Accounts Receivable $ 3,048 $ 2,820
Contract Assets 323 271
Contract Liabilities 140 116
Contract with customer, liability, revenue recognized 98 36
Unregulated Distributed Generation    
Disaggregation of Revenue [Line Items]    
Contract Assets 67 91
Contract Liabilities 95 115
Alabama Power    
Disaggregation of Revenue [Line Items]    
Accounts Receivable 783 821
Contract Assets 3 2
Contract Liabilities 11 0
Georgia Power    
Disaggregation of Revenue [Line Items]    
Accounts Receivable 1,244 1,011
Contract Assets 184 121
Contract Liabilities 34 1
Mississippi Power    
Disaggregation of Revenue [Line Items]    
Accounts Receivable 113 90
Contract Assets 0 0
Contract Liabilities 0 0
Southern Power    
Disaggregation of Revenue [Line Items]    
Accounts Receivable 106 122
Contract Assets 0 0
Contract Liabilities 2 4
Southern Company Gas    
Disaggregation of Revenue [Line Items]    
Accounts Receivable 660 684
Contract Assets 72 56
Contract Liabilities 3 $ 0
Southern Company Gas | Energy Efficiency Enhancement And Upgrade    
Disaggregation of Revenue [Line Items]    
Contract Liabilities $ 68