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REGULATORY MATTERS - APC Accounting Orders and Plant Greene County (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Public Utilities, General Disclosures [Line Items]
Other deferred charges and assets	$ 19,069	$ 20,148
Alabama Power
Public Utilities, General Disclosures [Line Items]
Other deferred charges and assets	$ 5,090	5,372
Percent ownership	14.00%
Alabama Power | Software Accounting Order
Public Utilities, General Disclosures [Line Items]
Other deferred charges and assets	$ 59	46
Mississippi Power
Public Utilities, General Disclosures [Line Items]
Other deferred charges and assets	$ 887	$ 828
Mississippi Power | Plant Greene County Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Percent ownership			40.00%

X

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets, excluding Property, Plant, and Equipment and Other Property and Investments, that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer.

+ References

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X

- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 360
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479960/980-360-S99-1

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- Definition

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