Regulatory Matters - GPC Amendments to the Vogtle Joint Ownership Agreements (Details) - USD ($) $ in Millions				1 Months Ended	3 Months Ended	9 Months Ended	12003 Months Ended
	Oct. 17, 2023	Oct. 05, 2023	Jan. 11, 2018	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022	Jul. 31, 2022	Jun. 30, 2022	Aug. 31, 2018
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 CO
Public Utilities, General Disclosures [Line Items]
Pre-tax charge to income					$ 160		$ 407
After tax charge to income					120		304
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO
Public Utilities, General Disclosures [Line Items]
Production tax credits, aggregate purchase price, maximum						$ 300
Preliminary estimated cost to complete					$ 10,753	$ 10,753
Additional construction capital costs			$ 3,300
Remaining share of construction costs, agreement to pay, percentage						100.00%
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
Estimated cost to complete, starting dollar amount								$ 18,380
Pre-tax charge to income							$ 567
Proportionate ownership share					45.70%	45.70%
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs	$ 17	$ 308
Remaining share of construction costs, agreement to pay, percentage		66.00%
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Vogtle Owners | Tender Provision Dispute
Public Utilities, General Disclosures [Line Items]
Estimated cost to complete, starting dollar amount									$ 17,100
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | MEAG Power
Public Utilities, General Disclosures [Line Items]
Payment of power costs				$ 92
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Oglethorpe Power Corporation | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Payment of power costs		$ 105
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Dalton Utilities | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Payment of power costs	$ 6
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category I
Public Utilities, General Disclosures [Line Items]
Preliminary estimated cost to complete					$ 8,400	$ 8,400
Additional construction capital costs, threshold						$ 800
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category II
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay						55.70%
Additional construction capital costs						$ 80
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category II | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay						44.30%
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category II | Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold						$ 800
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category II | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold						$ 1,600
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category III
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay						65.70%
Additional construction capital costs						$ 100
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category III | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay						34.30%
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category III | Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold						$ 1,600
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category III | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold						$ 2,100