REGULATORY MATTERS - Nuclear Construction (Details) - GEORGIA POWER CO $ in Millions								1 Months Ended		3 Months Ended	12 Months Ended
	Jan. 01, 2021	Apr. 15, 2020	Feb. 19, 2020 USD ($)	Feb. 18, 2020 USD ($)	Jan. 01, 2020	Jan. 11, 2018 USD ($)	Jan. 01, 2016	Dec. 31, 2019 USD ($)	Dec. 31, 2018 appeal	Mar. 31, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2012 utility MW	Dec. 31, 2009 USD ($)	Jun. 30, 2019 report	Aug. 31, 2018	Jun. 30, 2018 USD ($)	Dec. 31, 2013
Loss Contingencies [Line Items]
Number of construction units approved | utility															2
Electric generating capacity in mega watts under consortium agreement | MW															1,100
Estimated in-service capital cost																$ 4,418
Financing costs collected, net of tax										$ 2,300
Increase (decrease) in NCCR tariff								$ (62)
Additional construction capital costs						$ 3,300
Amendment to estimated in-service capital cost						$ 5,680
Retail rate of return on common equity																				10.95%
Number of appeals | appeal									2
Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Proportionate ownership share										45.70%
Construction contingency estimate, subject to rate recovery evaluation										$ 66									$ 366
Construction contingency estimate, subject to rate recovery evaluation, cumulative amount allocated to base capital cost forecast										206
Construction financing costs										2,300
Base project capital cost forecast, monthly										50
Monthly AFUDC										$ 10
Percentage of ownership interest required for voting for continuing construction																		90.00%
Percentage of costs, disallowed for recovery										6.00%
Costs disallowed for recovery, period										6 months
Public utilities, extension project schedule, term										1 year
Production tax credits, aggregate purchase price, maximum										$ 300
Remaining share of construction costs, agreement to pay, percentage										100.00%
Preliminary estimated cost to complete										$ 8,400
Cost settlement agreement revised forecast, net of payments										$ 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
Plant Vogtle Units 3 And 4 | Scenario, Forecast
Loss Contingencies [Line Items]
Construction financing costs													$ 3,100
Public utilities, approved return on equity percentage	5.30%
Return on equity reduction, negative impact on earnings											$ 200	$ 255	$ 145
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 First Vogtle Construction Monitoring Report | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Number of approved VCM reports | report																	21
Requested capital construction costs				$ 6,700
Guarantor obligations				1,700
Customer refund				$ 188
Twenty Second Vogtle Construction Monitoring Report | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Requested capital construction costs			$ 674
Maximum | COVID-19
Loss Contingencies [Line Items]
Estimate of possible loss										$ 20
Subsequent Event | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Expected percentage of positions eliminated		20.00%
Category I | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										800
Preliminary estimated cost to complete										$ 8,400
Category II | 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 | Plant Vogtle Units 3 And 4 | Vogtle Owners
Loss Contingencies [Line Items]
Percentage of construction costs, responsibility to pay										44.30%
Category II | Minimum | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										$ 800
Category II | Maximum | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										$ 1,600
Category III | 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 | Plant Vogtle Units 3 And 4 | Vogtle Owners
Loss Contingencies [Line Items]
Percentage of construction costs, responsibility to pay										34.30%
Category III | Maximum | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Additional construction capital costs, threshold										$ 2,100