Regulatory Matters - GPC Nuclear Construction (Details) - GEORGIA POWER CO $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2012 utility MW	Aug. 31, 2018
Loss Contingencies [Line Items]
Estimated cost to complete, pre-tax charge to income	$ 32	$ 36
Estimated cost to complete, pre-tax charge to income, net of tax	$ 24	27
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
Estimated cost to complete, construction contingency estimate, financing costs	$ 3,400		$ 3,400
Estimated cost to complete, construction contingency estimate, financing costs, incurred to date	3,100		3,100
Construction contingency estimate	170		170
Estimated cost to complete, additional construction contingency estimate	32	$ 36	32
Base project capital cost forecast, monthly			15
Monthly AFUDC			$ 35
Percentage of ownership interest required for voting for continuing construction					90.00%
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
Minimum | Plant Vogtle Units 3 And 4 | COVID-19
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss, loss of productivity, term			3 months
Estimate of possible loss	160		$ 160
Maximum | Plant Vogtle Units 3 And 4 | COVID-19
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss, loss of productivity, term			4 months
Estimate of possible loss	$ 200		$ 200