Condensed Consolidated Balance Sheets (Unaudited) - GAS - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 713	$ 748
Receivables —
Customer accounts	2,191	2,030
Unbilled revenues	620	786
Other accounts and notes	512	519
Accumulated provision for uncollectible accounts	(78)	(68)
Materials and supplies	2,063	1,989
Natural gas for sale	210	420
Prepaid expenses	474	406
Other regulatory assets	1,066	1,120
Other current assets	763	569
Total current assets	10,543	10,432
Property, Plant, and Equipment:
In service	129,228	128,428
Less: Accumulated depreciation	38,347	37,725
Plant in service, net of depreciation	90,881	90,703
Construction work in progress	8,225	7,784
Total property, plant, and equipment	100,470	99,844
Other Property and Investments:
Goodwill	5,161	5,161
Equity investments in unconsolidated subsidiaries	1,395	1,368
Other intangible assets, net of amortization	359	368
Miscellaneous property and investments	673	665
Total other property and investments	10,100	9,986
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,400	1,432
Prepaid pension costs	2,184	2,079
Other regulatory assets, deferred	6,318	6,264
Other deferred charges and assets	1,578	1,468
Total deferred charges and other assets	19,007	19,069
Total Assets	140,120	139,331
Current Liabilities:
Notes payable	2,445	2,314
Accounts payable —
Customer deposits	456	503
Accrued interest	583	652
Accrued compensation	618	1,151
Natural gas cost over recovery	150	214
Other regulatory liabilities	169	141
Other current liabilities	1,108	1,029
Total current liabilities	11,458	13,467
Long-term Debt	59,361	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,195	10,990
Deferred credits related to income taxes	4,607	4,674
Employee benefit obligations	1,096	1,115
Operating lease obligations, deferred	1,292	1,307
Other cost of removal obligations	1,989	1,957
Other deferred credits and liabilities	1,074	1,031
Total deferred credits and other liabilities	33,687	33,429
Total Liabilities	104,506	104,106
Total Stockholders' Equity	35,614	35,225
Total Liabilities and Stockholders' Equity	140,120	139,331
SOUTHERN Co GAS
Current Assets:
Cash and cash equivalents	77	33
Receivables —
Customer accounts	474	405
Unbilled revenues	204	261
Other accounts and notes	53	47
Accumulated provision for uncollectible accounts	(52)	(44)
Materials and supplies	68	66
Natural gas for sale	210	420
Prepaid expenses	60	107
Other regulatory assets	162	141
Other current assets	57	50
Total current assets	1,313	1,486
Property, Plant, and Equipment:
In service	21,078	20,840
Less: Accumulated depreciation	5,620	5,534
Plant in service, net of depreciation	15,458	15,306
Construction work in progress	1,112	1,110
Total property, plant, and equipment	16,570	16,416
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,260	1,235
Other intangible assets, net of amortization	14	16
Miscellaneous property and investments	26	25
Total other property and investments	6,315	6,291
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	46	47
Prepaid pension costs	164	158
Other regulatory assets, deferred	503	504
Other deferred charges and assets	180	181
Total deferred charges and other assets	893	890
Total Assets	25,091	25,083
Current Liabilities:
Notes payable	334	415
Accounts payable —
Customer deposits	79	126
Accrued taxes	84	77
Accrued interest	76	77
Accrued compensation	57	112
Natural gas cost over recovery	150	214
Other regulatory liabilities	60	19
Other current liabilities	172	155
Total current liabilities	1,364	1,708
Long-term Debt	7,825	7,833
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,736	1,671
Deferred credits related to income taxes	752	759
Employee benefit obligations	105	110
Operating lease obligations, deferred	38	40
Other cost of removal obligations	1,804	1,771
Accrued environmental remediation	194	192
Other deferred credits and liabilities	199	196
Total deferred credits and other liabilities	4,828	4,739
Total Liabilities	14,017	14,280
Total Stockholders' Equity	11,074	10,803
Total Liabilities and Stockholders' Equity	25,091	25,083
SOUTHERN Co GAS | Related Party
Accounts payable —
Affiliated and Other	44	89
SOUTHERN Co GAS | Nonrelated Party
Accounts payable —
Affiliated and Other	$ 308	$ 424