Consolidated Statements of Income - GAS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Revenues:
Total operating revenues	$ 23,113	$ 20,375	$ 21,419
Operating Expenses:
Other operations and maintenance	6,088	5,413	5,624
Depreciation and amortization	3,565	3,518	3,038
Taxes other than income taxes	1,290	1,234	1,230
Impairment charges	2	0	168
Gain on dispositions, net	(186)	(65)	(2,569)
Total operating expenses	19,415	15,490	13,683
Operating Income	3,698	4,885	7,736
Other Income and (Expense):
Earnings from equity method investments	76	153	162
Interest expense, net of amounts capitalized	(1,837)	(1,821)	(1,736)
Other income (expense), net	456	336	252
Total other income and (expense)	(1,122)	(1,389)	(1,194)
Earnings Before Income Taxes	2,576	3,496	6,542
Income taxes (benefit)	267	393	1,798
Consolidated Net Income	2,393	3,119	4,739
Natural gas
Operating Revenues:
Total operating revenues	4,380	3,434	3,792
Operating Expenses:
Cost of sales	1,619	972	1,319
Southern Company Gas
Operating Revenues:
Total operating revenues	4,380	3,434	3,792
Operating Expenses:
Other operations and maintenance	1,072	966	888
Depreciation and amortization	536	500	487
Taxes other than income taxes	225	206	213
Impairment charges	0	0	115
Gain on dispositions, net	(127)	(22)	0
Total operating expenses	3,325	2,622	3,022
Operating Income	1,055	812	770
Other Income and (Expense):
Earnings from equity method investments	50	141	157
Interest expense, net of amounts capitalized	(238)	(231)	(232)
Other income (expense), net	(53)	41	20
Total other income and (expense)	(241)	(49)	(55)
Earnings Before Income Taxes	814	763	715
Income taxes (benefit)	275	173	130
Consolidated Net Income	539	590	585
Southern Company Gas | Natural gas
Operating Revenues:
Total operating revenues	4,369	3,431	3,793
Operating Expenses:
Cost of sales	1,619	972	1,319
Southern Company Gas | Alternative revenue programs
Operating Revenues:
Total operating revenues	$ 11	$ 3	$ (1)