Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Deferred income taxes	608	89
Mark-to-market adjustments	(33)	147
Gain on dispositions, net	(41)	(171)
Natural gas cost under recovery – long-term	207	(79)
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Natural gas for sale, net of temporary LIFO liquidation	(136)	20
Natural gas cost under recovery	(124)	(432)
Other current assets	(343)	(180)
Accounts payable	805	(45)
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Property additions	(5,502)	(5,222)
Cost of removal, net of salvage	(518)	(282)
Proceeds from dispositions	120	160
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Financing Activities:
Decrease in notes payable, net	(349)	(203)
Proceeds —
Short-term borrowings	1,200	325
Redemptions and repurchases —
Short-term borrowings	(900)	(25)
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Accrued property additions at year-end	872	915
SOUTHERN Co GAS
Operating Activities:
Net income (loss)	516	389
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	414	396
Deferred income taxes	109	289
Mark-to-market adjustments	(34)	147
Impairment of PennEast Pipeline investment	0	84
Gain on dispositions, net	(5)	(127)
Natural gas cost under recovery – long-term	207	(79)
Other, net	27	32
Changes in certain current assets and liabilities —
Receivables	301	311
Natural gas for sale, net of temporary LIFO liquidation	(136)	20
Prepaid income taxes	(77)	(148)
Natural gas cost under recovery	(124)	(432)
Other current assets	7	(98)
Accounts payable	342	30
Other current liabilities	(15)	(57)
Net cash provided from operating activities	1,532	757
Investing Activities:
Property additions	(1,063)	(1,045)
Cost of removal, net of salvage	(84)	(74)
Construction payables	(103)	4
Proceeds from dispositions	0	126
Other investing activities	11	23
Net cash used for investing activities	(1,239)	(966)
Financing Activities:
Decrease in notes payable, net	(749)
Increase in notes payable, net		38
Proceeds —
Short-term borrowings	50	300
First mortgage bonds	100	100
Proceeds — Senior notes	500	450
Redemptions and repurchases —
Short-term borrowings	(150)	0
Senior notes	0	(300)
Medium-term notes	(46)	(30)
Capital contributions from parent company	357	63
Payment of common stock dividends	(389)	(397)
Other financing activities	14	(2)
Net cash provided from financing activities	(313)	222
Net Change in Cash, Cash Equivalents, and Restricted Cash	(20)	13
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	48	19
Cash, Cash Equivalents, and Restricted Cash at End of Period	28	32
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	186	173
Income taxes, net	193	85
Noncash transactions —
Accrued property additions at year-end	$ 10	$ 146