REGULATORY MATTERS - GPC Joint Ownership Agreements (Details) - USD ($) $ in Millions				1 Months Ended	3 Months Ended			12 Months Ended
	Oct. 17, 2023	Oct. 05, 2023	Sep. 29, 2022	Sep. 30, 2022	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2023
Public Utilities, General Disclosures [Line Items]
Agreement with third party, amount of costs over projected forecast to be paid by company			20.00%
Georgia Power
Public Utilities, General Disclosures [Line Items]
Pre-tax charge to income						$ 160	$ 407	$ 567
After tax charge to income						$ 120	$ 304
Plant Vogtle Units 3 and 4 | Georgia Power
Public Utilities, General Disclosures [Line Items]
Ownership interest percentage required for voting for continuing construction					90.00%			90.00%
Production tax credits, aggregate purchase price (up to)								$ 300
Preliminary estimated cost to complete					$ 10,753			$ 10,753
Additional construction capital costs	$ 17	$ 308
Remaining share of construction costs, agreement to pay, percentage		66.00%						100.00%
Percentage of costs, disallowed for recovery								6.00%
Costs disallowed for recovery, period								6 months
Public utilities, extension project schedule, term								1 year
Pre-tax charge to income					228
After tax charge to income					$ 170
Percent ownership					45.70%			45.70%
Plant Vogtle Units 3 and 4 | Georgia Power | MEAG Power
Public Utilities, General Disclosures [Line Items]
Agreement with third party, expected cost				$ 92
Plant Vogtle Units 3 and 4 | Georgia Power | Category I
Public Utilities, General Disclosures [Line Items]
Preliminary estimated cost to complete					$ 8,400			$ 8,400
Additional construction capital costs, threshold								800
Plant Vogtle Units 3 and 4 | Georgia Power | Category II
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs								$ 80
Percentage of construction costs responsible to pay								55.70%
Plant Vogtle Units 3 and 4 | Georgia Power | Category II | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs responsible to pay								44.30%
Plant Vogtle Units 3 and 4 | Georgia Power | Category II | Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold								$ 800
Plant Vogtle Units 3 and 4 | Georgia Power | Category II | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold								1,600
Plant Vogtle Units 3 and 4 | Georgia Power | Category III
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs								$ 100
Percentage of construction costs responsible to pay								65.70%
Plant Vogtle Units 3 and 4 | Georgia Power | Category III | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs responsible to pay								34.30%
Plant Vogtle Units 3 and 4 | Georgia Power | Category III | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold								$ 2,100