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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES- Storm Damage Reserves (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Balance at December 31, 2022 | $ 216 |
Balance at December 31, 2023 | 66 |
Accrual |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Accrual | 61 |
Weather-related damages |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Weather-related damages | (211) |
Alabama Power |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Balance at December 31, 2022 | 97 |
Balance at December 31, 2023 | 76 |
Alabama Power | Accrual |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Accrual | 18 |
Alabama Power | Weather-related damages |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Weather-related damages | (39) |
Georgia Power |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Balance at December 31, 2022 | 83 |
Balance at December 31, 2023 | (54) | $ (83)
Georgia Power | Accrual |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Accrual | 31 |
Georgia Power | Weather-related damages |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Weather-related damages | (168) |
Mississippi Power |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Balance at December 31, 2022 | 36 |
Balance at December 31, 2023 | 44 |
Mississippi Power | Accrual |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Accrual | 12 |
Mississippi Power | Weather-related damages |  |
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] |  |
Weather-related damages | $ (4) |

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