Contingencies and Regulatory Matters - Textual - SO Regulatory GPC (Details) $ in Millions		1 Months Ended	12 Months Ended		84 Months Ended
	Jan. 01, 2013	Jul. 31, 2016 MW	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) MW	Dec. 31, 2022	Jun. 30, 2019 USD ($)	Dec. 31, 2016 USD ($)	Aug. 31, 2016	May 01, 2016 USD ($)	Jan. 01, 2016 USD ($)	Dec. 31, 2015 USD ($)
Schedule of Regulatory Assets and Liabilities [Line Items]
Other regulatory assets, current				$ 604			$ 581
Other regulatory assets, deferred				$ 6,943			6,851
Scenario, Forecast | Customers
Schedule of Regulatory Assets and Liabilities [Line Items]
Percentage basis net merger savings					60.00%
Georgia Power And Atlanta Gas Light Company | Scenario, Forecast
Schedule of Regulatory Assets and Liabilities [Line Items]
Percentage basis net merger savings					40.00%
GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Increase (decrease) in base tariff rate										$ 49
Increase (decrease) in ECCR tariff										75
Increase (decrease) in demand side management tariff										3
Increase (decrease) in municipal franchise fee tariff										13
Increase (decrease) in revenue to be received from base rate change										$ 140
Retail rate of return on common equity	10.95%
Portion of actual earnings above approved ROE band retained by subsidiary company	33.33%
Portion of actual earnings above approved ROE band refunded to customers	66.67%
Capacity of units included in application request by subsidiaries for future period requests | MW		1,200
Capacity of renewable resources approved for self-build | MW		200
Approved capacity of units for solar generation resources | MW				510
Approved increase (decrease) in annual billing based on fuel cost recovery rate									$ (313)		$ (350)
Adjustment to fuel cost recovery rate if under recovered fuel balance exceeds budget thereafter				$ 200
Required period for options and hedges				48 months
Over recovered fuel balance				$ 165			84
Accrual under alternate rate plan				30
Other regulatory assets, current				205			193
Other regulatory assets, deferred				2,932			2,774
GEORGIA POWER CO | Scenario, Forecast
Schedule of Regulatory Assets and Liabilities [Line Items]
Customer refund			$ 44
Minimum | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Retail rate of return on common equity	10.00%
Maximum | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Retail rate of return on common equity	12.00%
Capacity of renewable resources considered for renewable commercial and industrial program | MW		200
Maximum | GEORGIA POWER CO | Scenario, Forecast
Schedule of Regulatory Assets and Liabilities [Line Items]
Cost recovery, new nuclear						$ 99
Cost recovery, estimate, nuclear fuel						$ 50
Plant Mitchell Units 3, 4A, and 4B | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Capacity of units included in request for decertification of units | MW		217
Plant Kraft Unit 1 | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Capacity of units included in request for decertification of units | MW		17
Intercession City Combustion Turbine | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Capacity of units included in request to sell | MW		143
Percent ownership								33.00%
Storm damage reserves | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Incremental restoration costs				260
Property damage reserves-liability | GEORGIA POWER CO
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory asset				333			206
Other regulatory assets, current				30			30
Other regulatory assets, deferred				$ 303			$ 176