Liability For Unpaid Claims And Claims Adjustment Expense, Certain Additional Amounts, Period Increase (Decrease)

No definition available.

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- Definition

Public Utilities, Deferred Amount, Reliability Reserve

+ References

No definition available.

+ Details

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- Definition

Regulatory Asset, Accrual

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Regulatory Asset, Weather-Related Damages

+ References

No definition available.

+ Details

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Namespace Prefix:	so_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Regulatory Liability, Period Charge

+ References

No definition available.

+ Details

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Namespace Prefix:	so_
Data Type:	xbrli:monetaryItemType
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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.W.Q2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479583/944-40-S99-1

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after effects of reinsurance, of increase (decrease) in the liability for unpaid claims and claims adjustment expense.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-3

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 340
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478742/980-340-50-1

+ Details

Name:	us-gaap_RegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
-SubTopic 405
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477571/980-405-25-1

+ Details

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Period Type:	instant

- Details

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- Details

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Balance Type:
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- Details

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Storm Damage and Reliability Reserves (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended			24 Months Ended
	Jan. 01, 2023	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2022	Apr. 11, 2024	Apr. 30, 2023	Mar. 31, 2023
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023	$ 216.0		$ 66.0	$ 216.0
Balance at December 31, 2024				66.0	$ 216.0	$ 216.0
Balance at December 31, 2024			(705.0)
Reliability reserve, amount deferred			84.0	63.0	191.0	191.0
Major storms
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Storm damage reserves					239.0
Accrual
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			79.0	61.0
Weather-related damages
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(850.0)	(211.0)
Alabama Power
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023	97.0		76.0	97.0
Balance at December 31, 2024			70.0	76.0	97.0	97.0
Reliability reserve, amount deferred			63.0	52.0	166.0	166.0
Alabama Power \| Major storms
Liability for Catastrophe Claims [Line Items]
Additional accruals authorized by state PSCs			21.0
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Storm damage reserves					19.0
Alabama Power \| Accrual
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			34.0	18.0
Alabama Power \| Weather-related damages
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(40.0)	(39.0)
Charges against storm damage reserves			24.0
Georgia Power
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023	83.0			83.0
Balance at December 31, 2024					83.0	83.0
Balance at December 31, 2024			(827.0)	(54.0)
Storm damage reserves	31.0					213.0
Georgia Power \| Major storms
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages		$ (870.0)
Balance at December 31, 2024			750.0
Storm damage reserves					213.0
Georgia Power \| Accrual
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			31.0	31.0
Georgia Power \| Weather-related damages
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(804.0)	(168.0)
Charges against storm damage reserves			82.0
Mississippi Power
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023	$ 36.0		44.0	36.0
Balance at December 31, 2024			52.0	44.0	36.0	36.0
Reliability reserve, amount deferred			21.0	11.0	25.0	$ 25.0	$ 12.6	$ 11.7	$ 8.3
Mississippi Power \| Major storms
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Storm damage reserves			12.6	11.7	$ 6.9
Mississippi Power \| Accrual
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			14.0	12.0
Mississippi Power \| Weather-related damages
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(6.0)	$ (4.0)
Charges against storm damage reserves			$ 0.0