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DERIVATIVES - Energy-Related Derivative Contracts (Details) - Energy-related, Natural Gas MMBTU in Millions | Dec. 31, 2023 MMBTU
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Derivative [Line Items] |
Net Purchased mmBtu | 448.0
Alabama Power |
Derivative [Line Items] |
Net Purchased mmBtu | 118.0
Georgia Power |
Derivative [Line Items] |
Net Purchased mmBtu | 128.0
Mississippi Power |
Derivative [Line Items] |
Net Purchased mmBtu | 93.0
Southern Power |
Derivative [Line Items] |
Net Purchased mmBtu | 7.0
Southern Company Gas |
Derivative [Line Items] |
Net Purchased mmBtu | 102.0
Long | Not Designated as Hedging Instrument | Southern Company Gas |
Derivative [Line Items] |
Derivative nonmonetary notional amount net long short position volume | 112.0
Short | Not Designated as Hedging Instrument | Southern Company Gas |
Derivative [Line Items] |
Derivative nonmonetary notional amount net long short position volume | 10.0

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