REGULATORY MATTERS - Nuclear Construction (Details) $ in Millions						1 Months Ended			3 Months Ended	9 Months Ended	12 Months Ended
	Jan. 01, 2021	Aug. 31, 2020 USD ($)	Jan. 01, 2020	Jan. 11, 2018 USD ($)	Jan. 01, 2016	Apr. 30, 2020	Dec. 31, 2019 USD ($) report	Dec. 31, 2018 appeal	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) report	Dec. 31, 2012 utility MW	Dec. 31, 2009 USD ($)	Jun. 30, 2020 USD ($)	Aug. 31, 2018	Jun. 30, 2018 USD ($)	Dec. 31, 2013
Loss Contingencies [Line Items]
Construction contingency estimate									$ 5	$ 5
GEORGIA POWER CO
Loss Contingencies [Line Items]
Additional construction capital costs				$ 3,300
Estimated in-service capital cost																$ 4,418
Financing costs collected, net of tax										$ 2,500
Decrease in NCCR tariff							$ 142
Amendment to estimated in-service capital cost				$ 5,680
Retail rate of return on common equity																				10.95%
Number of appeals | appeal								2
GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Proportionate ownership share									45.70%	45.70%
Number of construction units approved | utility															2
Electric generating capacity in mega watts under consortium agreement | MW															1,100
Construction costs incurred										$ 2,500
Construction contingency estimate																			$ 366
Construction contingency estimate, amount in excess of original estimate																	$ 34
Construction contingency estimate, additional amount									$ 115	115
Estimated loss on Plant Vogtle Units 3 and 4									149	149
Estimated loss on plants under construction, after tax									111	111
Expected percentage of positions eliminated						20.00%
Base project capital cost forecast, monthly										50
Monthly AFUDC										10
Percentage of ownership interest required for voting for continuing construction																		90.00%
Production tax credits, aggregate purchase price, maximum										300
Preliminary estimated cost to complete									8,500	$ 8,500
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
Cost settlement agreement revised forecast, net of payments									7,300	$ 7,300
Public utilities, approved return on equity percentage			8.30%		10.00%
Public utilities, approved return on equity, monthly percentage decrease										0.10%
Return on equity reduction, negative impact on earnings														$ 75
GEORGIA POWER CO | Plant Vogtle Units 3 And 4 | Scenario, Forecast
Loss Contingencies [Line Items]
Construction costs incurred													$ 3,000
Public utilities, approved return on equity percentage	5.30%
Return on equity reduction, negative impact on earnings											$ 200	$ 255	$ 145
GEORGIA POWER CO | Plant Vogtle Units 3 And 4 | Vogtle Owners
Loss Contingencies [Line Items]
Period of notice required in the event letters of credit are not renewed										30 days
Twenty Second Construction Monitoring Report | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Number of approved construction management reports | report							22							22
Requested capital construction costs														$ 7,400
Guarantor obligations							$ 1,700							1,700
Customer refund														$ 188
Twenty Third Construction Monitoring Report | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Requested capital construction costs		$ 701
Minimum | GEORGIA POWER CO | COVID-19
Loss Contingencies [Line Items]
Estimate of possible loss									70	$ 70
Maximum | GEORGIA POWER CO
Loss Contingencies [Line Items]
Retail rate of return on common equity							12.00%							12.00%
Maximum | GEORGIA POWER CO | COVID-19
Loss Contingencies [Line Items]
Estimate of possible loss									115	115
Category I | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Preliminary estimated cost to complete									$ 8,400	8,400
Additional construction capital costs, threshold										$ 800
Category II | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Percentage of construction costs, responsibility to pay										55.70%
Additional construction capital costs										$ 80
Category II | GEORGIA POWER CO | Plant Vogtle Units 3 And 4 | Vogtle Owners
Loss Contingencies [Line Items]
Percentage of construction costs, responsibility to pay										44.30%
Category II | Minimum | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										$ 800
Category II | Maximum | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										$ 1,600
Category III | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Percentage of construction costs, responsibility to pay										65.70%
Additional construction capital costs										$ 100
Category III | GEORGIA POWER CO | Plant Vogtle Units 3 And 4 | Vogtle Owners
Loss Contingencies [Line Items]
Percentage of construction costs, responsibility to pay										34.30%
Category III | Maximum | GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										$ 2,100