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FINANCING - Dividend Restrictions and Structural Considerations Narrative (Details) $ in Billions | 12 Months Ended
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Dec. 31, 2023 USD ($)
Variable Interest Entity [Line Items] |
Undistributed retained earnings of subsidiaries | $ 5.5
Southern Company Gas |
Variable Interest Entity [Line Items] |
Retained earnings, unappropriated | $ 1.7
Southern Company Gas | Southern Company Gas Capital |
Variable Interest Entity [Line Items] |
Noncontrolling ownership percentage held by parent | 100.00%

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