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CONTINGENCIES, COMMITMENTS, AND GUARANTEES - Environmental Remediation (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Georgia Power |  |  |
Environmental Exit Cost [Line Items] |  |  |
Costs recovered annually | $ 5,000,000 | $ 5,000,000 | $ 12,000,000
Environmental remediation liability, current | 13,000,000 | 14,000,000 |
Accrued environmental remediation | 0 | 0 |
Under recovered environmental remediation costs, other regulatory assets, current | 5,000,000 | 5,000,000 |
Under recovered environmental remediation costs, other regulatory assets, deferred | 11,000,000 | 15,000,000 |
Southern Company Gas |  |  |
Environmental Exit Cost [Line Items] |  |  |
Environmental remediation liability, current | 24,000,000 | 30,000,000 |
Accrued environmental remediation | 198,000,000 | 192,000,000 |
Under recovered environmental remediation costs, other regulatory assets, current | 32,000,000 | 40,000,000 |
Under recovered environmental remediation costs, other regulatory assets, deferred | 201,000,000 | 195,000,000 |
Alabama Power |  |  |
Environmental Exit Cost [Line Items] |  |  |
Environmental remediation liability, current | 0 | 0 |
Southern Company |  |  |
Environmental Exit Cost [Line Items] |  |  |
Environmental remediation liability, current | 37,000,000 | 44,000,000 |
Accrued environmental remediation | 198,000,000 | 192,000,000 |
Under recovered environmental remediation costs, other regulatory assets, current | 37,000,000 | 45,000,000 |
Under recovered environmental remediation costs, other regulatory assets, deferred | $ 212,000,000 | $ 210,000,000 |
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] | Other Liabilities, Current | Other Liabilities, Current |

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