ASSET RETIREMENT OBLIGATIONS - Accumulated Provisions for the External Decommissioning Trust Funds (Details) - External decommissioning trust funds - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Georgia Power
Public Utilities, General Disclosures [Line Items]
Accumulated provisions for decommissioning	$ 1,405	$ 1,236
Plant Farley | Alabama Power
Public Utilities, General Disclosures [Line Items]
Accumulated provisions for decommissioning	1,540	1,385
Plant Hatch | Georgia Power
Public Utilities, General Disclosures [Line Items]
Accumulated provisions for decommissioning	825	735
Plant Vogtle Units 1 and 2 | Georgia Power
Public Utilities, General Disclosures [Line Items]
Accumulated provisions for decommissioning	519	460
Plant Vogtle Units 3 and 4 | Georgia Power
Public Utilities, General Disclosures [Line Items]
Accumulated provisions for decommissioning	$ 61	$ 41