Regulatory Matters - GPC Nuclear Construction (Details) - GEORGIA POWER CO $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($)	Dec. 31, 2012 utility MW	Oct. 06, 2023 pump	Sep. 20, 2023 USD ($)	Aug. 31, 2018
Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Proportionate ownership share	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	$ 3,500
Estimated cost to complete, construction contingency estimate, financing costs, incurred to date	3,400
Construction contingency estimate				$ 43
Monthly AFUDC	$ 25
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
Plant Vogtle Unit 4 | Subsequent Event
Loss Contingencies [Line Items]
Number of RPCs | pump			1
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
Maximum | Plant Vogtle Units 3 And 4 | Subsequent Event
Loss Contingencies [Line Items]
Number of RPCs | pump			7
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
Maximum | Plant Vogtle Unit 4 | Subsequent Event
Loss Contingencies [Line Items]
Number of RPCs | pump			4