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Introduction - Storm Damage Reserves and Depreciation (Details) - USD ($) $ in Millions		1 Months Ended		6 Months Ended
	Apr. 01, 2025	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2025
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2024				$ 705
Balance at June 30, 2025		$ 867	$ 705	867
Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual				36
Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages				(198)
ALABAMA POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2024
Balance at December 31, 2024				(70)
Balance at June 30, 2025		2		2
Balance at June 30, 2025			(70)
Amount awarded			7
Asset retirement obligation, period decrease		257
ALABAMA POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual				13
ALABAMA POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages				(85)
GEORGIA POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2024				827
Balance at June 30, 2025		917	827	917
GEORGIA POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual				16
GEORGIA POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages				(106)
MISSISSIPPI POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2024				(52)
Balance at June 30, 2025		(52)	$ (52)	(52)
Approved rate increase (decrease)	$ 8
Asset retirement obligation, period decrease		$ 13
MISSISSIPPI POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual				7
MISSISSIPPI POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages				$ (7)

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-Topic 410
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-Section 50
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