Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating Activities:
Consolidated net income	$ 3,053	$ 3,566
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,699	3,084
Deferred income taxes	(52)	608
Natural gas cost under recovery – long-term	0	207
Other, net	(67)	(119)
Changes in certain current assets and liabilities —
Receivables	524	(316)
Natural gas cost under recovery	108	(124)
Other current assets	(32)	(310)
Accounts payable	(1,031)	805
Other current liabilities	66	(82)
Net cash provided from operating activities	5,740	5,017
Investing Activities:
Property additions	(6,561)	(5,502)
Cost of removal, net of salvage	(421)	(518)
Change in construction payables, net	241	15
Other investing activities	(139)	(63)
Net cash used for investing activities	(6,721)	(5,952)
Financing Activities:
Decrease in notes payable, net	(298)	(349)
Proceeds —
Short-term borrowings	250	1,200
Redemptions —
Short-term borrowings	(850)	(900)
Payment of common stock dividends	(2,271)	(2,166)
Other financing activities	(141)	(235)
Net cash provided from financing activities	834	1,119
Net Change in Cash, Cash Equivalents, and Restricted Cash	(147)	184
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,890	2,013
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,694	1,425
Income taxes, net	11	160
Accrued property additions at end of period	1,224	872
Right-of-use assets obtained under operating leases	76	27
SOUTHERN Co GAS
Operating Activities:
Consolidated net income	475	516
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	429	414
Deferred income taxes	75	109
Natural gas cost under recovery – long-term	0	207
Other, net	(15)	(12)
Changes in certain current assets and liabilities —
Receivables	776	301
Natural gas for sale, net of temporary LIFO liquidation	31	(136)
Prepaid income taxes	12	(77)
Natural gas cost under recovery	108	(124)
Other current assets	(32)	7
Accounts payable	(346)	342
Natural gas cost over recovery	165	0
Other current liabilities	(34)	(15)
Net cash provided from operating activities	1,644	1,532
Investing Activities:
Property additions	(1,151)	(1,063)
Cost of removal, net of salvage	(82)	(84)
Change in construction payables, net	(38)	(103)
Other investing activities	45	11
Net cash used for investing activities	(1,226)	(1,239)
Financing Activities:
Decrease in notes payable, net	(493)	(749)
Proceeds —
Proceeds — Senior notes	500	500
First mortgage bonds	125	100
Short-term borrowings	0	50
Other long-term debt	29	0
Redemptions —
Short-term borrowings	(200)	(150)
Medium-term notes	0	(46)
Capital contributions from parent company	377	357
Payment of common stock dividends	(439)	(389)
Other financing activities	(1)	14
Net cash provided from financing activities	(102)	(313)
Net Change in Cash, Cash Equivalents, and Restricted Cash	316	(20)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	83	48
Cash, Cash Equivalents, and Restricted Cash at End of Period	399	28
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	214	186
Income taxes, net	70	193
Accrued property additions at end of period	139	10
Right-of-use assets obtained under operating leases	$ 3	$ 0