Consolidated Balance Sheets - GAS - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 1,798	$ 1,065
Receivables —
Energy marketing	0	516
Customer accounts	1,806	1,753
Unbilled revenues	711	672
Other accounts and notes	523	512
Accumulated provision for uncollectible accounts	(78)	(118)
Natural gas for sale	362	460
Prepaid expenses	330	276
Assets from risk management activities, net of collateral	151	147
Natural gas cost under recovery	266	0
Other regulatory assets	653	810
Other current assets	231	282
Total current assets	8,965	8,617
Property, Plant, and Equipment:
In service	115,592	110,516
Less: Accumulated depreciation	34,079	32,397
Plant in service, net of depreciation	81,513	78,119
Construction work in progress	8,771	8,697
Total property, plant, and equipment	91,108	87,634
Other Property and Investments:
Goodwill	5,280	5,280
Equity investments in unconsolidated subsidiaries	1,282	1,362
Other intangible assets, net of amortization	445	487
Miscellaneous property and investments	653	398
Total other property and investments	10,202	10,386
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,701	1,802
Prepaid pension costs	1,657	0
Other regulatory assets, deferred	5,577	7,198
Other deferred charges and assets	1,776	1,288
Total deferred charges and other assets	17,259	16,298
Total Assets	127,534	122,935
Current Liabilities:
Securities due within one year	2,157	3,507
Notes payable	1,440	609
Energy marketing trade payables	0	494
Accounts payable —
Customer deposits	479	487
Accrued interest	533	513
Accrued compensation	1,070	1,025
Other regulatory liabilities	563	509
Other current liabilities	872	968
Total current liabilities	10,921	12,079
Long-Term Debt	50,120	45,073
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	8,862	8,175
Deferred credits related to income taxes	5,401	5,767
Employee benefit obligations	1,550	2,213
Operating lease obligations, deferred	1,503	1,611
Other cost of removal obligations	2,103	2,211
Other deferred credits and liabilities	816	696
Total deferred credits and other liabilities	33,926	33,258
Total Liabilities	94,967	90,410
Common Stockholders' Equity:
Common stock	5,279	5,268
Retained earnings (accumulated deficit)	10,929	11,311
Accumulated other comprehensive loss	(237)	(395)
Total Stockholders' Equity (See accompanying statements)	32,276	32,234
Total Liabilities and Stockholders' Equity	127,534	122,935
Commitments and Contingent Matters (See notes)
Southern Company Gas
Current Assets:
Cash and cash equivalents	45	17
Receivables —
Energy marketing	0	516
Customer accounts	462	353
Unbilled revenues	278	219
Other accounts and notes	49	55
Accumulated provision for uncollectible accounts	(39)	(40)
Natural gas for sale	362	460
Prepaid expenses	114	48
Assets from risk management activities, net of collateral	33	118
Natural gas cost under recovery	266	0
Other regulatory assets	136	102
Other current assets	49	38
Total current assets	1,755	1,886
Property, Plant, and Equipment:
In service	18,880	17,611
Less: Accumulated depreciation	5,067	4,821
Plant in service, net of depreciation	13,813	12,790
Construction work in progress	684	648
Total property, plant, and equipment	14,497	13,438
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,173	1,290
Other intangible assets, net of amortization	37	51
Miscellaneous property and investments	19	19
Total other property and investments	6,244	6,375
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	70	81
Prepaid pension costs	175	70
Other regulatory assets, deferred	689	615
Other deferred charges and assets	130	165
Total deferred charges and other assets	1,064	931
Total Assets	23,560	22,630
Current Liabilities:
Securities due within one year	47	333
Notes payable	1,209	324
Energy marketing trade payables	0	494
Accounts payable —
Affiliated	58	56
Other	361	373
Customer deposits	95	90
Accrued taxes	124	83
Accrued interest	59	58
Accrued compensation	110	106
Other regulatory liabilities	8	122
Other current liabilities	155	150
Total current liabilities	2,226	2,189
Long-Term Debt	6,855	6,293
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,555	1,265
Deferred credits related to income taxes	816	847
Employee benefit obligations	176	283
Operating lease obligations, deferred	59	67
Other cost of removal obligations	1,683	1,649
Accrued environmental remediation	197	216
Other deferred credits and liabilities	77	54
Total deferred credits and other liabilities	4,563	4,381
Total Liabilities	13,644	12,863
Common Stockholders' Equity:
Common stock	10,024	9,930
Retained earnings (accumulated deficit)	(132)	(141)
Accumulated other comprehensive loss	24	(22)
Total Stockholders' Equity (See accompanying statements)	9,916	9,767
Total Liabilities and Stockholders' Equity	23,560	22,630
Commitments and Contingent Matters (See notes)