Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 1,770	$ 1,065
Receivables —
Customer accounts	1,716	1,753
Energy marketing	412	516
Unbilled revenues	544	672
Other accounts and notes	478	512
Accumulated provision for uncollectible accounts	(124)	(118)
Materials and supplies	1,504	1,478
Fossil fuel for generation	494	550
Natural gas for sale	197	460
Prepaid expenses	657	276
Assets from risk management activities, net of collateral	100	147
Regulatory assets – asset retirement obligations	214	214
Natural gas cost under recovery	487	0
Other regulatory assets	788	810
Other current assets	232	282
Total current assets	9,469	8,617
Property, Plant, and Equipment:
In service	111,579	110,516
Less: Accumulated depreciation	32,887	32,397
Plant in service, net of depreciation	78,692	78,119
Nuclear fuel, at amortized cost	820	818
Construction work in progress	9,525	8,697
Total property, plant, and equipment	89,037	87,634
Other Property and Investments:
Goodwill	5,280	5,280
Nuclear decommissioning trusts, at fair value	2,346	2,303
Equity investments in unconsolidated subsidiaries	1,368	1,362
Other intangible assets, net of amortization	477	487
Leveraged leases	562	556
Miscellaneous property and investments	463	398
Total other property and investments	10,496	10,386
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,821	1,802
Deferred charges related to income taxes	803	796
Unamortized loss on reacquired debt	274	280
Regulatory assets – asset retirement obligations, deferred	4,966	4,934
Other regulatory assets, deferred	7,263	7,198
Other deferred charges and assets	1,264	1,288
Total deferred charges and other assets	16,391	16,298
Total Assets	125,393	122,935
Current Liabilities:
Securities due within one year	3,535	3,507
Notes payable	1,092	609
Energy marketing trade payables	475	494
Accounts payable —
Accounts payable	2,058	2,312
Customer deposits	470	487
Accrued taxes —
Accrued income taxes	71	130
Other accrued taxes	412	699
Accrued interest	423	513
Accrued compensation	584	1,025
Asset retirement obligations	642	585
Operating lease obligations	244	241
Other regulatory liabilities	462	509
Other current liabilities	1,118	968
Total current liabilities	11,586	12,079
Long-term Debt	46,727	45,073
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	8,839	8,175
Deferred credits related to income taxes	5,676	5,767
Accumulated deferred ITCs	2,214	2,235
Employee benefit obligations	2,091	2,213
Operating lease obligations, deferred	1,652	1,611
Asset retirement obligations, deferred	10,043	10,099
Accrued environmental remediation	208	216
Other cost of removal obligations	2,215	2,211
Other regulatory liabilities, deferred	226	251
Other deferred credits and liabilities	557	480
Total deferred credits and other liabilities	33,721	33,258
Total Liabilities	92,034	90,410
Redeemable Preferred Stock of Subsidiaries	291	291
Common Stockholder's Equity (See accompanying statements)	33,068	32,234
Total Liabilities and Stockholders' Equity	125,393	122,935
ALABAMA POWER CO
Current Assets:
Cash and cash equivalents	619	530
Receivables —
Customer accounts	394	429
Unbilled revenues	124	152
Affiliated	35	31
Other accounts and notes	71	66
Accumulated provision for uncollectible accounts	(33)	(43)
Materials and supplies	550	546
Fossil fuel for generation	197	235
Prepaid expenses	114	42
Other regulatory assets	224	226
Other current assets	43	33
Total current assets	2,338	2,247
Property, Plant, and Equipment:
In service	32,015	31,816
Less: Accumulated depreciation	10,123	10,009
Plant in service, net of depreciation	21,892	21,807
Nuclear fuel, at amortized cost	268	270
Construction work in progress	1,052	866
Total property, plant, and equipment	23,212	22,943
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,198	1,157
Equity investments in unconsolidated subsidiaries	63	63
Miscellaneous property and investments	128	131
Total other property and investments	1,389	1,351
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	140	151
Deferred charges related to income taxes	237	235
Regulatory assets – asset retirement obligations, deferred	1,446	1,441
Other regulatory assets, deferred	2,161	2,162
Other deferred charges and assets	282	273
Total deferred charges and other assets	4,266	4,262
Total Assets	31,205	30,803
Current Liabilities:
Securities due within one year	815	311
Accounts payable —
Affiliated	220	316
Other	392	545
Customer deposits	105	104
Accrued taxes —
Accrued taxes	257	152
Accrued interest	75	90
Accrued compensation	113	212
Asset retirement obligations	275	254
Other regulatory liabilities	98	108
Other current liabilities	108	107
Total current liabilities	2,458	2,199
Long-term Debt	8,055	8,558
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,318	3,273
Deferred credits related to income taxes	2,006	2,016
Accumulated deferred ITCs	92	94
Employee benefit obligations	187	214
Operating lease obligations, deferred	112	119
Asset retirement obligations, deferred	3,688	3,720
Other cost of removal obligations	320	335
Other regulatory liabilities, deferred	98	124
Other deferred credits and liabilities	54	50
Total deferred credits and other liabilities	9,875	9,945
Total Liabilities	20,388	20,702
Redeemable Preferred Stock	291	291
Common Stockholder's Equity (See accompanying statements)	10,526	9,810
Total Liabilities and Stockholders' Equity	31,205	30,803
GEORGIA POWER CO
Current Assets:
Cash and cash equivalents	29	9
Receivables —
Customer accounts	532	621
Unbilled revenues	196	233
Joint owner accounts	124	123
Affiliated	22	21
Other accounts and notes	35	67
Accumulated provision for uncollectible accounts	(26)	(26)
Materials and supplies	610	592
Fossil fuel for generation	268	278
Regulatory assets – storm damage	213	213
Regulatory assets – asset retirement obligations	175	166
Other regulatory assets	250	248
Other current assets	114	143
Total current assets	2,542	2,688
Property, Plant, and Equipment:
In service	39,857	39,682
Less: Accumulated depreciation	12,421	12,251
Plant in service, net of depreciation	27,436	27,431
Nuclear fuel, at amortized cost	553	548
Construction work in progress	7,394	6,857
Total property, plant, and equipment	35,383	34,836
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,149	1,145
Equity investments in unconsolidated subsidiaries	51	51
Miscellaneous property and investments	66	63
Total other property and investments	1,266	1,259
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,273	1,308
Deferred charges related to income taxes	532	527
Regulatory assets – asset retirement obligations, deferred	3,310	3,291
Other regulatory assets, deferred	2,609	2,692
Other deferred charges and assets	434	479
Total deferred charges and other assets	8,158	8,297
Total Assets	47,349	47,080
Current Liabilities:
Securities due within one year	87	542
Notes payable	205	60
Accounts payable —
Affiliated	472	597
Other	732	753
Customer deposits	272	276
Accrued taxes —
Accrued taxes	239	407
Accrued interest	96	130
Accrued compensation	123	233
Asset retirement obligations	304	287
Operating lease obligations	151	151
Other regulatory liabilities	235	228
Over recovered fuel clause revenues	83	113
Other current liabilities	242	254
Total current liabilities	3,241	4,031
Long-term Debt	13,278	12,428
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,303	3,272
Deferred credits related to income taxes	2,517	2,588
Accumulated deferred ITCs	271	273
Employee benefit obligations	539	586
Operating lease obligations, deferred	1,149	1,156
Asset retirement obligations, deferred	5,971	5,978
Other deferred credits and liabilities	306	267
Total deferred credits and other liabilities	14,056	14,120
Total Liabilities	30,575	30,579
Common Stockholder's Equity (See accompanying statements)	16,774	16,501
Total Liabilities and Stockholders' Equity	47,349	47,080
MISSISSIPPI POWER CO
Current Assets:
Cash and cash equivalents	24	39
Receivables —
Customer accounts	50	34
Unbilled revenues	33	38
Affiliated	17	32
Other accounts and notes	29	32
Materials and supplies	67	65
Fossil fuel for generation	17	24
Other regulatory assets	49	60
Other current assets	20	20
Total current assets	306	344
Property, Plant, and Equipment:
In service	5,037	5,011
Less: Accumulated depreciation	1,579	1,545
Plant in service, net of depreciation	3,458	3,466
Construction work in progress	163	146
Total property, plant, and equipment	3,621	3,612
Other Property and Investments:
Total other property and investments	149	151
Deferred Charges and Other Assets:
Deferred charges related to income taxes	32	32
Regulatory assets – asset retirement obligations, deferred	211	201
Other regulatory assets, deferred	386	388
Accumulated deferred income taxes	126	129
Other deferred charges and assets	64	55
Total deferred charges and other assets	819	805
Total Assets	4,895	4,912
Current Liabilities:
Securities due within one year	421	406
Notes payable	54	25
Accounts payable —
Affiliated	50	63
Other	84	109
Accrued taxes —
Accrued taxes	39	114
Accrued interest	14	15
Accrued compensation	18	34
Asset retirement obligations	40	27
Other regulatory liabilities	36	49
Over recovered fuel clause revenues	26	34
Other current liabilities	38	40
Total current liabilities	820	916
Long-term Debt	996	1,013
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	463	447
Deferred credits related to income taxes	285	287
Employee benefit obligations	107	113
Asset retirement obligations, deferred	134	150
Other cost of removal obligations	194	194
Other regulatory liabilities, deferred	14	15
Other deferred credits and liabilities	34	35
Total deferred credits and other liabilities	1,231	1,241
Total Liabilities	3,047	3,170
Common Stockholder's Equity (See accompanying statements)	1,848	1,742
Total Liabilities and Stockholders' Equity	4,895	4,912
SOUTHERN POWER CO
Current Assets:
Cash and cash equivalents	314	182
Receivables —
Customer accounts	123	125
Affiliated	17	37
Other accounts and notes	18	27
Materials and supplies	157	157
Prepaid income taxes	368	11
Other current assets	31	36
Total current assets	1,028	575
Property, Plant, and Equipment:
In service	14,313	13,904
Less: Accumulated depreciation	2,916	2,842
Plant in service, net of depreciation	11,397	11,062
Construction work in progress	219	127
Total property, plant, and equipment	11,616	11,189
Other Property and Investments:
Intangible assets, net of amortization	297	302
Equity investments in unconsolidated subsidiaries	84	19
Miscellaneous property and investments	84	19
Total other property and investments	381	321
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	478	415
Prepaid LTSAs	178	155
Accumulated deferred income taxes	0	262
Income taxes receivable, non-current	28	25
Other deferred charges and assets	286	293
Total deferred charges and other assets	970	1,150
Total Assets	13,995	13,235
Current Liabilities:
Securities due within one year	300	299
Notes payable	315	175
Accounts payable —
Affiliated	44	65
Other	127	92
Accrued taxes —
Accrued income taxes	10	8
Other accrued taxes	15	22
Accrued interest	35	32
Other current liabilities	132	132
Total current liabilities	978	825
Long-term Debt	3,730	3,393
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	230	123
Accumulated deferred ITCs	1,658	1,672
Operating lease obligations, deferred	487	426
Other deferred credits and liabilities	168	165
Total deferred credits and other liabilities	2,543	2,386
Total Liabilities	7,251	6,604
Common Stockholder's Equity (See accompanying statements)	6,744	6,631
Total Liabilities and Stockholders' Equity	13,995	13,235
SOUTHERN Co GAS
Current Assets:
Cash and cash equivalents	309	17
Receivables —
Customer accounts	452	353
Energy marketing	412	516
Unbilled revenues	161	219
Affiliated	2	4
Other accounts and notes	43	51
Accumulated provision for uncollectible accounts	(51)	(40)
Natural gas for sale	197	460
Prepaid expenses	97	48
Assets from risk management activities, net of collateral	68	118
Natural gas cost under recovery	487	0
Other regulatory assets	84	102
Other current assets	39	38
Total current assets	2,300	1,886
Property, Plant, and Equipment:
In service	17,866	17,611
Less: Accumulated depreciation	4,893	4,821
Plant in service, net of depreciation	12,973	12,790
Construction work in progress	636	648
Total property, plant, and equipment	13,609	13,438
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,290	1,290
Other intangible assets, net of amortization	47	51
Miscellaneous property and investments	20	19
Total other property and investments	6,372	6,375
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	80	81
Other regulatory assets, deferred	786	615
Other deferred charges and assets	230	235
Total deferred charges and other assets	1,096	931
Total Assets	23,377	22,630
Current Liabilities:
Securities due within one year	302	333
Notes payable	497	324
Energy marketing trade payables	475	494
Accounts payable —
Affiliated	49	56
Other	346	373
Customer deposits	76	90
Accrued taxes —
Accrued taxes	94	83
Accrued interest	68	58
Accrued compensation	107	106
Other regulatory liabilities	92	122
Temporary LIFO liquidation	194	0
Other current liabilities	166	150
Total current liabilities	2,466	2,189
Long-term Debt	6,286	6,293
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,427	1,265
Deferred credits related to income taxes	839	847
Employee benefit obligations	273	283
Operating lease obligations, deferred	65	67
Accrued environmental remediation	208	216
Other cost of removal obligations	1,668	1,649
Other deferred credits and liabilities	51	54
Total deferred credits and other liabilities	4,531	4,381
Total Liabilities	13,283	12,863
Common Stockholder's Equity (See accompanying statements)	10,094	9,767
Total Liabilities and Stockholders' Equity	$ 23,377	$ 22,630