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Natural Disaster Reserve Authorized Limit

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Natural Disaster Reserve, Expected Recovery Amount

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Regulatory Asset, Accrual

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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A credit or adjustment for government or taxing authority authorized decrease in taxes owed as a result of meeting certain tax policy conditions.

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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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The net amount of all regulatory assets less all regulatory liabilities as of the end of the period.

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Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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Regulatory Matters - Alabama Power (Details) $ in Millions		1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
Regulatory Matters - Alabama Power (Details) $ in Millions	Jun. 06, 2025 USD ($)	Oct. 29, 2025 USD ($)	Sep. 30, 2025 USD ($) MW	Dec. 31, 2025 USD ($)	Dec. 31, 2026 USD ($)	Jun. 19, 2025 USD ($)	Jun. 05, 2025 USD ($)	Dec. 31, 2024 USD ($)
Loss Contingencies [Line Items]
Regulatory asset balance related to storm damage			$ 856					$ 705
ALABAMA POWER CO
Loss Contingencies [Line Items]
Regulatory asset balance related to storm damage			4
Minimum natural disaster reserve balance, triggering establishment charge			50
Natural disaster reserve authorized limit			75
ALABAMA POWER CO \| Subsequent Event
Loss Contingencies [Line Items]
Federal income tax return credit		$ 180
ALABAMA POWER CO \| Reliability Reserve Liability
Loss Contingencies [Line Items]
Regulatory liability			101			$ 131
Decrease in accrual			30
ALABAMA POWER CO \| Regulatory Liability, Nuclear PTC
Loss Contingencies [Line Items]
Regulatory liability			$ 36
ALABAMA POWER CO \| Jurisdictional Separation Study Order (JSS)
Loss Contingencies [Line Items]
Regulatory asset balance related to storm damage							$ 100
Regulatory asset amortization period							10 years
ALABAMA POWER CO \| Tenaska Alabama Partners, L.P.
Loss Contingencies [Line Items]
Approximate nameplate capacity \| MW			855
Purchase price	$ 635
ALABAMA POWER CO \| Scenario, Forecast
Loss Contingencies [Line Items]
Natural disaster reserve, expected recovery amount				$ 18	$ 36