Property, Plant, and Equipment - Joint Ownership Agreements (Narrative) (Details) - USD ($)	60 Months Ended
	Jan. 15, 2024	Dec. 31, 2018	Dec. 04, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Construction work in progress		$ 7,254,000,000		$ 6,904,000,000
Georgia Power
Property, Plant and Equipment [Line Items]
Construction work in progress		4,833,000,000		4,613,000,000
Southern Power
Property, Plant and Equipment [Line Items]
Construction work in progress		430,000,000		511,000,000
Mississippi Power
Property, Plant and Equipment [Line Items]
Construction work in progress		$ 103,000,000		$ 84,000,000
Plant Vogtle Units 3 And 4 | Georgia Power
Property, Plant and Equipment [Line Items]
Percent ownership		45.70%
Construction work in progress		$ 4,500,000,000
Plant Stanton Unit A | Southern Power
Property, Plant and Equipment [Line Items]
Ownership percentage sold			65.00%
Subsequent Event | Scenario, Forecast | Plant Daniel Units 1 And 2 | Gulf Power
Property, Plant and Equipment [Line Items]
Ownership interest to be sold	50.00%
Ownership interest in one unit	100.00%
Subsequent Event | Scenario, Forecast | Plant Daniel Units 1 And 2 | Mississippi Power
Property, Plant and Equipment [Line Items]
Payments to acquire businesses	$ 1
Option to purchase, period	120 days