Consolidated Statements of Income - GAS - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Revenues:
Total operating revenues	$ 29,553,000,000	$ 26,724,000,000	$ 25,253,000,000
Operating Expenses:
Other operations and maintenance	7,066,000,000	6,518,000,000	6,025,000,000
Depreciation and amortization	5,501,000,000	4,755,000,000	4,525,000,000
Taxes other than income taxes	1,538,000,000	1,540,000,000	1,425,000,000
Total operating expenses	22,268,000,000	19,656,000,000	19,427,000,000
Operating Income	7,285,000,000	7,068,000,000	5,826,000,000
Other Income and (Expense):
Earnings from equity method investments	112,000,000	139,000,000	144,000,000
Interest expense, net of amounts capitalized	(3,238,000,000)	(2,743,000,000)	(2,446,000,000)
Other income (expense), net	500,000,000	530,000,000	553,000,000
Total other income and (expense)	(2,286,000,000)	(1,839,000,000)	(1,481,000,000)
Earnings Before Income Taxes	4,999,000,000	5,229,000,000	4,345,000,000
Income taxes	828,000,000	969,000,000	496,000,000
Net Income	4,341,000,000	4,401,000,000	3,976,000,000
Southern Company Gas
Operating Revenues:
Total operating revenues	5,044,000,000	4,456,000,000	4,702,000,000
Operating Expenses:
Cost of natural gas	1,599,000,000	1,196,000,000	1,644,000,000
Other operations and maintenance	1,297,000,000	1,235,000,000	1,187,000,000
Depreciation and amortization	708,000,000	650,000,000	582,000,000
Taxes other than income taxes	272,000,000	248,000,000	262,000,000
Estimated loss on regulatory disallowance	63,000,000	0	88,000,000
Total operating expenses	3,939,000,000	3,329,000,000	3,763,000,000
Operating Income	1,105,000,000	1,127,000,000	939,000,000
Other Income and (Expense):
Earnings from equity method investments	127,000,000	146,000,000	140,000,000
Interest expense, net of amounts capitalized	(377,000,000)	(341,000,000)	(310,000,000)
Other income (expense), net	59,000,000	66,000,000	57,000,000
Total other income and (expense)	(191,000,000)	(129,000,000)	(113,000,000)
Earnings Before Income Taxes	914,000,000	998,000,000	826,000,000
Income taxes	182,000,000	258,000,000	211,000,000
Net Income	$ 732,000,000	$ 740,000,000	$ 615,000,000