Introduction - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 2,123	$ 1,917
Restricted cash:
Total cash, cash equivalents, and restricted cash	2,244	2,037	$ 1,735	$ 1,829
Other current assets
Restricted cash:
Restricted cash	83	62
Other deferred charges and assets
Restricted cash:
Restricted cash	39	58
GEORGIA POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	44	364
Restricted cash:
Total cash, cash equivalents, and restricted cash	160	480	230	33
GEORGIA POWER CO | Other current assets
Restricted cash:
Restricted cash	80	60
GEORGIA POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	36	56
GEORGIA POWER CO | Proceeds From Issuance Of Solid Waste Disposal Facility Revenue Bonds
Restricted cash:
Restricted cash	116	116
SOUTHERN POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	169	131
Restricted cash:
Total cash, cash equivalents, and restricted cash	172	133	211	135
SOUTHERN POWER CO | Other current assets
Restricted cash:
Restricted cash	0	0
SOUTHERN POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	3	3
SOUTHERN POWER CO | Estimated Construction Completion Costs | Deuel Harvest
Restricted cash:
Restricted cash	3	3
SOUTHERN Co GAS
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	242	81
Restricted cash:
Total cash, cash equivalents, and restricted cash	244	83	$ 218	$ 48
SOUTHERN Co GAS | Other current assets
Restricted cash:
Restricted cash	3	2
SOUTHERN Co GAS | Other deferred charges and assets
Restricted cash:
Restricted cash	$ 0	$ 0