REGULATORY MATTERS - GPC Joint Ownership Agreements (Details) - USD ($) $ in Thousands			3 Months Ended				12 Months Ended
	Oct. 04, 2022	Sep. 29, 2022	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2016	Jun. 18, 2022
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]
Amortization period							5 years
Pre-tax charge to income			$ 53,000	$ (102,000)	$ 16,000	$ 440,000	$ 407,000
After tax charge to income			$ 40,000	$ (76,000)	$ 12,000	$ 328,000
Plant Vogtle Units 3 and 4 | Georgia Power
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs	$ 345,000							$ 3,300,000
Ownership interest percentage required for voting for continuing construction			90.00%				90.00%
Production tax credits, aggregate purchase price (up to)							$ 300,000
Preliminary estimated cost to complete			$ 10,593,000				$ 10,593,000
Remaining share of construction costs, agreement to pay, percentage							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
Estimated cost to complete, starting dollar amount			$ 18,380,000				$ 18,380,000
Percent ownership			45.70%				45.70%
Plant Vogtle Units 3 and 4 | Georgia Power | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs							$ 100
Plant Vogtle Units 3 and 4 | Georgia Power | Vogtle Owners | Tender Provision Dispute
Public Utilities, General Disclosures [Line Items]
Estimated cost to complete, starting dollar amount									$ 17,100,000
Plant Vogtle Units 3 and 4 | Georgia Power | MEAG Power
Public Utilities, General Disclosures [Line Items]
Agreement with third party, expected cost		$ 92,000
Plant Vogtle Units 3 and 4 | Georgia Power | Category I
Public Utilities, General Disclosures [Line Items]
Preliminary estimated cost to complete			$ 8,400,000				8,400,000
Additional construction capital costs, threshold							800,000
Plant Vogtle Units 3 and 4 | Georgia Power | Category II
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs							$ 80,000
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							$ 800,000
Plant Vogtle Units 3 and 4 | Georgia Power | Category II | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold							1,600,000
Plant Vogtle Units 3 and 4 | Georgia Power | Category III
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs							$ 100,000
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							$ 2,100,000