FINANCING - Maturities of Long-Term Debt (Details) $ in Millions	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
2024	$ 2,480
2025	4,124
2026	3,791
2027	2,075
2028	2,612
Alabama Power
Debt Instrument [Line Items]
2024	223
2025	251
2026	46
2027	551
2028	107
Alabama Power \| Series 2023A Convertible Senior Notes Due 2025
Debt Instrument [Line Items]
2024	200
Georgia Power
Debt Instrument [Line Items]
2024	503
2025	849
2026	448
2027	512
2028	864
Mississippi Power
Debt Instrument [Line Items]
2024	201
2025	12
2026	66
2027	10
2028	357
Southern Power
Debt Instrument [Line Items]
2024	0
2025	500
2026	964
2027	0
2028	0
Southern Power \| Euro-denominated Debt
Debt Instrument [Line Items]
2028	564
Southern Company Gas
Debt Instrument [Line Items]
2024	0
2025	300
2026	530
2027	154
2028	$ 150

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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