Financing and Leases - Bank Credit Agreements Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 30, 2024
Debt Instrument [Line Items]
Expires, 2025	$ 580
Variable rate pollution control revenue bonds outstanding	1,700
MISSISSIPPI POWER CO
Debt Instrument [Line Items]
Restated amount of LOC	150	$ 125
Expires, 2025	0
Variable rate pollution control revenue bonds outstanding	69
ALABAMA POWER CO
Debt Instrument [Line Items]
Expires, 2025	0
Variable rate pollution control revenue bonds outstanding	796
Fixed rate pollution control revenue bonds outstanding	207
GEORGIA POWER CO
Debt Instrument [Line Items]
Expires, 2025	300
Variable rate pollution control revenue bonds outstanding	819
Fixed rate pollution control revenue bonds outstanding	157
Southern Company parent
Debt Instrument [Line Items]
Expires, 2025	150
SOUTHERN Co GAS
Debt Instrument [Line Items]
Expires, 2025	100
SEGCO
Debt Instrument [Line Items]
Expires, 2025	$ 30

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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