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Deferred Income Taxes, Excess Accumulated Amount, Period

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Reliability Reserve, Reliability-Related Transmission, Distribution, And Generation Expenses

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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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Amount of public utility's approved rate increase (decrease) by regulatory agency.

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Percentage of public utility's approved rate increase (decrease) by regulatory agency.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

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Regulatory Matters - Mississippi Power (Details) - MISSISSIPPI POWER CO - USD ($) $ in Millions	Jun. 18, 2026	Jun. 12, 2026	Apr. 14, 2026	Mar. 02, 2026	Jun. 30, 2026	Mar. 16, 2026
Loss Contingencies [Line Items]
Deferred Income Taxes, Excess Accumulated Amount	$ 21.0
Deferred Income Taxes, Excess Accumulated Amount, Period	18 months
Plant Daniel Units 1 and 2
Loss Contingencies [Line Items]
Remaining net book value					$ 481.0
Reliability Reserve Liability
Loss Contingencies [Line Items]
Reliability reserve expense	$ 7.0
Remaining net book value					$ 52.0	$ 59.0
Mississippi PSC PEP Filing
Loss Contingencies [Line Items]
Approved rate increase (decrease)	$ 20.0
Approved rate increase (decrease)	1.80%
Mississippi PSC
Loss Contingencies [Line Items]
Approved rate increase (decrease)			$ 2.0
Mississippi PSC SRR Filing
Loss Contingencies [Line Items]
Approved rate increase (decrease)				$ 13.7
Minimum annual accrual, amount				$ 13.5
Ad Valorem Tax Adjustment
Loss Contingencies [Line Items]
Requested rate increase amount		$ 7.0