Regulatory Matters - GPC Amendments to the Vogtle Joint Ownership Agreements (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
	Jan. 11, 2018	Sep. 30, 2022	Mar. 31, 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				$ 407,000
After tax charge to income				304,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO
Public Utilities, General Disclosures [Line Items]
Production tax credits, aggregate purchase price, maximum			$ 300,000
Preliminary estimated cost to complete			$ 10,593,000
Additional construction capital costs	$ 3,300,000			$ 345,000
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					$ 18,380,000
Proportionate ownership share			45.70%
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs			$ 100
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						$ 17,100,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | MEAG Power
Public Utilities, General Disclosures [Line Items]
Payment of power costs		$ 92,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category I
Public Utilities, General Disclosures [Line Items]
Preliminary estimated cost to complete			8,400,000
Additional construction capital costs, threshold			$ 800,000
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			$ 80,000
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			$ 800,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category II | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold			$ 1,600,000
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			$ 100,000
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			$ 1,600,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category III | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold			$ 2,100,000