v3.25.0.1
VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Provision for uncollectible accounts:      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period $ 68 $ 71 $ 78
Charged to Income 119 87 71
Charged to Other Accounts (1) 3 (1)
Deductions 112 93 77
Balance at End of Period 74 68 71
Provision for uncollectible accounts: | Alabama Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 16 14 14
Charged to Income 26 16 10
Charged to Other Accounts 0 0 0
Deductions 20 14 10
Balance at End of Period 22 16 14
Provision for uncollectible accounts: | Georgia Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 4 3 2
Charged to Income 51 26 21
Charged to Other Accounts 0 0 0
Deductions 40 25 20
Balance at End of Period 15 4 3
Provision for uncollectible accounts: | Mississippi Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 1 1 1
Charged to Income 2 2 1
Charged to Other Accounts 0 0 1
Deductions 2 2 2
Balance at End of Period 1 1 1
Provision for uncollectible accounts: | Southern Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 1 1 5
Charged to Income (1) 0 (2)
Charged to Other Accounts 0 0 0
Deductions 0 0 2
Balance at End of Period 0 1 1
Provision for uncollectible accounts: | Southern Company Gas      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 44 50 39
Charged to Income 39 43 55
Charged to Other Accounts (1) 3 0
Deductions 49 52 44
Balance at End of Period 33 44 50
Tax valuation allowance (net state)      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 168 207 169
Charged to Income 97 (14) 68
Charged to Other Accounts 3 (25) (30)
Deductions 0 0 0
Balance at End of Period 268 168 207
Tax valuation allowance (net state) | Georgia Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 60 98 58
Charged to Income 97 (15) 70
Charged to Other Accounts (33) (23) (30)
Deductions 0 0 0
Balance at End of Period 124 60 98
Tax valuation allowance (net state) | Mississippi Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 32 32 32
Charged to Income 0 0 0
Charged to Other Accounts 0 0 0
Deductions 0 0 0
Balance at End of Period 32 32 32
Tax valuation allowance (net state) | Southern Power      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 21 21 21
Charged to Income 0 0 0
Charged to Other Accounts 0 0 0
Deductions 0 0 0
Balance at End of Period 21 21 21
Tax valuation allowance (net state) | Southern Company Gas      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Period 5 7 7
Charged to Income 0 0 0
Charged to Other Accounts (1) (2) 0
Deductions 0 0 0
Balance at End of Period $ 4 $ 5 $ 7