Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities:
Net income (loss)	$ 2,079	$ 1,482
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,995	1,949
Deferred income taxes	240	(101)
Mark-to-market adjustments	14	136
Natural gas cost under recovery – long-term	192	(119)
Other, net	21	117
Changes in certain current assets and liabilities —
Receivables	(637)	29
Natural gas for sale, net of temporary LIFO liquidation	335	375
Natural gas cost under recovery	(94)	(485)
Other current assets	12	94
Accounts payable	703	(177)
Accrued taxes	(150)	(157)
Other current liabilities	30	(235)
Net cash provided from operating activities	3,579	2,904
Investing Activities:
Property additions	(3,213)	(3,384)
Cost of removal, net of salvage	(377)	(184)
Other investing activities	96	(20)
Net cash used for investing activities	(3,460)	(4,026)
Financing Activities:
Increase (decrease) in notes payable, net	263	492
Proceeds —
Proceeds - Short-term borrowings	1,200	325
Redemptions and repurchases —
Short-term borrowings	(400)	(25)
Payment of common stock dividends	(1,425)	(1,377)
Net cash provided from (used for) financing activities	(213)	1,671
Net Change in Cash, Cash Equivalents, and Restricted Cash	(94)	549
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,735	1,617
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	836	884
Income taxes, net	157	88
Noncash transactions —
Accrued property additions at year-end	837	943
SOUTHERN Co GAS
Operating Activities:
Net income (loss)	433	333
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	275	263
Deferred income taxes	35	110
Mark-to-market adjustments	13	137
Impairment of PennEast Pipeline investment	0	82
Natural gas cost under recovery – long-term	192	(119)
Other, net	42	15
Changes in certain current assets and liabilities —
Receivables	244	262
Natural gas for sale, net of temporary LIFO liquidation	335	375
Prepaid income taxes	(70)	(129)
Natural gas cost under recovery	(94)	(485)
Other current assets	19	7
Accounts payable	101	(42)
Accrued taxes	(41)	1
Other current liabilities	(6)	(88)
Net cash provided from operating activities	1,478	722
Investing Activities:
Property additions	(637)	(635)
Cost of removal, net of salvage	(53)	(44)
Other investing activities	32	11
Net cash used for investing activities	(658)	(668)
Financing Activities:
Increase (decrease) in notes payable, net	(593)
Increase (decrease) in notes payable, net		210
Proceeds —
Proceeds - Short-term borrowings	50	300
Redemptions and repurchases —
Short-term borrowings	(150)	0
Senior notes	0	300
Medium-term notes	(46)	(30)
Capital contributions from parent company	349	60
Payment of common stock dividends	(260)	(265)
Net cash provided from (used for) financing activities	(650)	(25)
Net Change in Cash, Cash Equivalents, and Restricted Cash	170	29
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	48	19
Cash, Cash Equivalents, and Restricted Cash at End of Period	218	48
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	129	127
Income taxes, net	210	100
Noncash transactions —
Accrued property additions at year-end	$ 126	$ 137