Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating Revenues:
Operating revenues	$ 5,198	$ 4,620	$ 11,108	$ 9,638
Operating Expenses:
Total cost of sales	231	144	814	583
Other operations and maintenance	1,438	1,203	2,810	2,498
Depreciation and amortization	891	873	1,762	1,730
Taxes other than income taxes	313	298	657	629
Estimated loss on Plant Vogtle Units 3 and 4	460	149	508	149
(Gain) loss on dispositions, net	(11)	0	(54)	(39)
Total operating expenses	4,490	3,562	8,802	7,317
Operating Income	708	1,058	2,306	2,321
Other Income and (Expense):
Allowance for equity funds used during construction	45	35	90	68
Earnings (loss) from equity method investments	(40)	30	5	72
Interest expense, net of amounts capitalized	(450)	(444)	(901)	(900)
Impairment of leveraged leases	(7)	(154)	(7)	(154)
Other income (expense), net	108	101	167	204
Total other income and (expense)	(344)	(432)	(646)	(710)
Earnings (Loss) Before Income Taxes	364	626	1,660	1,611
Income taxes (benefit)	(12)	5	178	150
Consolidated Net Income	376	621	1,482	1,461
Dividends on preferred stock of subsidiaries	4	4	7	7
Net income (loss) attributable to noncontrolling interests	0	5	(33)	(26)
Net Income	$ 372	$ 612	$ 1,508	$ 1,480
Earnings per share -
Basic (in dollars per share)	$ 0.35	$ 0.58	$ 1.42	$ 1.40
Diluted (in dollars per share)	$ 0.35	$ 0.58	$ 1.41	$ 1.39
Average number of shares of common stock outstanding (in millions)
Basic (in shares)	1,061	1,058	1,060	1,057
Diluted (in shares)	1,067	1,063	1,066	1,065
Retail electric revenues
Operating Revenues:
Operating revenues	$ 3,599	$ 3,182	$ 6,941	$ 6,260
Wholesale electric revenues
Operating Revenues:
Operating revenues	546	472	1,091	889
Other electric revenues
Operating Revenues:
Operating revenues	175	168	346	320
Natural gas
Operating Revenues:
Operating revenues	677	636	2,371	1,885
Operating Expenses:
Total cost of sales	231	144	814	583
Other
Operating Revenues:
Operating revenues	201	162	359	284
Operating Expenses:
Total cost of sales	103	74	185	129
Fuel
Operating Expenses:
Total cost of sales	848	621	1,696	1,257
Purchased power
Operating Expenses:
Total cost of sales	217	200	424	381
Alternative revenue programs
Operating Revenues:
Operating revenues	2	(2)	4	7
ALABAMA POWER CO
Operating Revenues:
Operating revenues	1,556	1,365	3,115	2,716
Operating Expenses:
Other operations and maintenance	413	342	775	690
Depreciation and amortization	214	202	425	402
Taxes other than income taxes	101	102	203	208
Total operating expenses	1,078	924	2,123	1,853
Operating Income	478	441	992	863
Other Income and (Expense):
Allowance for equity funds used during construction	12	11	24	22
Interest expense, net of amounts capitalized	(84)	(83)	(168)	(171)
Other income (expense), net	33	26	62	48
Total other income and (expense)	(39)	(46)	(82)	(101)
Earnings (Loss) Before Income Taxes	439	395	910	762
Income taxes (benefit)	104	93	213	177
Consolidated Net Income	335	302	697	585
Dividends on preferred stock of subsidiaries	4	4	7	7
Net Income	331	298	690	578
ALABAMA POWER CO | Retail electric revenues
Operating Revenues:
Operating revenues	1,354	1,223	2,706	2,427
ALABAMA POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	85	54	178	111
ALABAMA POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Operating revenues	24	7	55	26
ALABAMA POWER CO | Other
Operating Revenues:
Operating revenues	93	81	176	152
ALABAMA POWER CO | Fuel
Operating Expenses:
Total cost of sales	263	199	554	415
ALABAMA POWER CO | Purchased power
Operating Expenses:
Total cost of sales	48	49	97	89
ALABAMA POWER CO | Purchased power, affiliates
Operating Expenses:
Total cost of sales	39	30	69	49
GEORGIA POWER CO
Operating Revenues:
Operating revenues	2,225	1,928	4,195	3,754
Operating Expenses:
Other operations and maintenance	542	463	1,015	928
Depreciation and amortization	342	354	680	707
Taxes other than income taxes	118	108	235	221
Estimated loss on Plant Vogtle Units 3 and 4	460	149	508	149
Total operating expenses	2,098	1,555	3,667	2,976
Operating Income	127	373	528	778
Other Income and (Expense):
Allowance for equity funds used during construction	30	20	61	40
Interest expense, net of amounts capitalized	(106)	(105)	(210)	(216)
Other income (expense), net	42	31	83	63
Total other income and (expense)	(34)	(54)	(66)	(113)
Earnings (Loss) Before Income Taxes	93	319	462	665
Income taxes (benefit)	(50)	11	(32)	27
Consolidated Net Income	143	308	494	638
GEORGIA POWER CO | Retail electric revenues
Operating Revenues:
Operating revenues	2,026	1,760	3,813	3,435
GEORGIA POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	36	25	80	51
GEORGIA POWER CO | Other
Operating Revenues:
Operating revenues	163	143	302	268
GEORGIA POWER CO | Fuel
Operating Expenses:
Total cost of sales	343	226	656	458
GEORGIA POWER CO | Purchased power
Operating Expenses:
Total cost of sales	144	133	288	262
GEORGIA POWER CO | Purchased power, affiliates
Operating Expenses:
Total cost of sales	149	122	285	251
MISSISSIPPI POWER CO
Operating Revenues:
Operating revenues	303	283	610	559
Operating Expenses:
Other operations and maintenance	76	67	144	142
Depreciation and amortization	44	46	91	88
Taxes other than income taxes	32	30	63	59
Total operating expenses	254	233	506	463
Operating Income	49	50	104	96
Other Income and (Expense):
Interest expense, net of amounts capitalized	(14)	(15)	(29)	(31)
Other income (expense), net	11	6	20	14
Total other income and (expense)	(3)	(9)	(9)	(17)
Earnings (Loss) Before Income Taxes	46	41	95	79
Income taxes (benefit)	8	2	12	8
Consolidated Net Income	38	39	83	71
MISSISSIPPI POWER CO | Retail electric revenues
Operating Revenues:
Operating revenues	219	199	422	398
MISSISSIPPI POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	54	52	117	103
MISSISSIPPI POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Operating revenues	25	25	57	47
MISSISSIPPI POWER CO | Other
Operating Revenues:
Operating revenues	5	7	14	11
MISSISSIPPI POWER CO | Fuel
Operating Expenses:
Total cost of sales	91	83	192	162
MISSISSIPPI POWER CO | Purchased power
Operating Expenses:
Total cost of sales	11	7	16	12
SOUTHERN POWER CO
Operating Revenues:
Operating revenues	490	439	930	814
Operating Expenses:
Other operations and maintenance	111	77	211	156
Depreciation and amortization	132	121	251	239
Taxes other than income taxes	12	10	24	19
(Gain) loss on dispositions, net	0	0	(39)	(39)
Total operating expenses	420	328	774	616
Operating Income	70	111	156	198
Other Income and (Expense):
Interest expense, net of amounts capitalized	(37)	(38)	(75)	(77)
Other income (expense), net	1	1	8	4
Total other income and (expense)	(36)	(37)	(67)	(73)
Earnings (Loss) Before Income Taxes	34	74	89	125
Income taxes (benefit)	(2)	6	(11)	13
Consolidated Net Income	36	68	100	112
Net income (loss) attributable to noncontrolling interests	0	5	(33)	(26)
Net Income	36	63	133	138
SOUTHERN POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	373	343	728	629
SOUTHERN POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Operating revenues	112	92	193	178
SOUTHERN POWER CO | Other
Operating Revenues:
Operating revenues	5	4	9	7
SOUTHERN POWER CO | Fuel
Operating Expenses:
Total cost of sales	140	102	281	209
SOUTHERN POWER CO | Purchased power
Operating Expenses:
Total cost of sales	25	18	46	32
SOUTHERN Co GAS
Operating Revenues:
Operating revenues	$ 677	$ 636	$ 2,371	$ 1,885
Operating Expenses:
Cost, Product and Service [Extensible Enumeration]	Natural gas	Natural gas	Natural gas	Natural gas
Other operations and maintenance	$ 233	$ 220	$ 532	$ 479
Depreciation and amortization	133	123	263	243
Taxes other than income taxes	49	47	130	118
Total operating expenses	646	534	1,739	1,423
Operating Income	31	102	632	462
Other Income and (Expense):
Earnings (loss) from equity method investments	(52)	30	(11)	72
Interest expense, net of amounts capitalized	(59)	(57)	(118)	(114)
Other income (expense), net	(14)	12	(78)	21
Total other income and (expense)	(125)	(15)	(207)	(21)
Earnings (Loss) Before Income Taxes	(94)	87	425	441
Income taxes (benefit)	(29)	16	92	95
Consolidated Net Income	(65)	71	333	346
SOUTHERN Co GAS | Natural gas
Operating Revenues:
Operating revenues	675	638	2,367	1,878
Operating Expenses:
Total cost of sales	231	144	814	583
SOUTHERN Co GAS | Alternative revenue programs
Operating Revenues:
Operating revenues	$ 2	$ (2)	$ 4	$ 7