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Income Taxes - Narrative (Details) - USD ($) $ in Millions | 6 Months Ended |
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Dec. 31, 2022
Income Tax Contingency [Line Items] |  |  |
Effective tax (benefit) rate | 10.70% | 18.70% |
ALABAMA POWER CO |  |  |
Income Tax Contingency [Line Items] |  |  |
Effective tax (benefit) rate | 3.90% | 23.60% |
GEORGIA POWER CO |  |  |
Income Tax Contingency [Line Items] |  |  |
Effective tax (benefit) rate | 15.80% | 16.40% |
Unrecognized tax positions | $ 48 |  |
SOUTHERN POWER CO |  |  |
Income Tax Contingency [Line Items] |  |  |
Effective tax (benefit) rate | (0.70%) | 11.20% |
Southern Company parent(a) |  |  |
Income Tax Contingency [Line Items] |  |  |
Unrecognized tax positions | $ 130 |  | $ 80
MISSISSIPPI POWER CO |  |  |
Income Tax Contingency [Line Items] |  |  |
Effective tax (benefit) rate | 15.20% | 18.80% |

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