Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating Revenues:
Total operating revenues	$ 6,159	$ 6,201	$ 18,158	$ 17,403
Operating Expenses:
Other operations and maintenance	1,404	1,341	4,217	4,100
Depreciation and amortization	787	767	2,338	2,236
Taxes other than income taxes	319	303	990	941
Estimated loss on plants under construction	1	34	1,105	3,155
Gain on dispositions, net	(353)	0	(317)	(19)
Impairment charges	36	0	197	0
Goodwill impairment			42
Total operating expenses	3,985	4,210	14,545	15,809
Operating Income (Loss)	2,174	1,991	3,613	1,594
Other Income and (Expense):
Allowance for equity funds used during construction	36	18	99	133
Earnings from equity method investments	36	32	108	100
Interest expense, net of amounts capitalized	(458)	(407)	(1,386)	(1,248)
Other income (expense), net	57	65	195	165
Total other income and (expense)	(329)	(292)	(984)	(850)
Earnings (Loss) Before Income Taxes	1,845	1,699	2,629	744
Income taxes	623	590	598	317
Consolidated net income (loss)	1,222	1,109	2,031	427
Dividends on preferred and preference stock of subsidiaries	4	10	12	32
Net income attributable to noncontrolling interests	54	30	71	48
Net Income (Loss)	$ 1,164	$ 1,069	$ 1,948	$ 347
Earnings per share -
Basic (in dollars per share)	$ 1.14	$ 1.07	$ 1.92	$ 0.35
Diluted (in dollars per share)	$ 1.13	$ 1.06	$ 1.91	$ 0.35
Average number of shares of common stock outstanding (in millions)
Basic (in shares)	1,023	1,003	1,016	998
Diluted (in shares)	1,029	1,010	1,021	1,005
Cash dividends paid per share of common stock (in dollars per share)	$ 0.60	$ 0.58	$ 1.78	$ 1.72
Retail electric revenues
Operating Revenues:
Total operating revenues	$ 4,605	$ 4,615	$ 11,913	$ 11,786
Wholesale electric revenues
Operating Revenues:
Total operating revenues	693	718	1,923	1,867
Other electric revenues
Operating Revenues:
Total operating revenues	170	168	509	510
Natural gas
Operating Revenues:
Total operating revenues	492	532	2,806	2,746
Operating Expenses:
Cost of goods and services sold	104	134	1,053	1,085
Alternative revenue programs
Operating Revenues:
Total operating revenues	5	0	(23)	9
Other
Operating Revenues:
Total operating revenues	199	168	1,007	494
Operating Expenses:
Cost of goods and services sold	120	90	688	293
Fuel
Operating Expenses:
Cost of goods and services sold	1,310	1,285	3,514	3,372
Purchased power
Operating Expenses:
Cost of goods and services sold	257	256	760	646
ALABAMA POWER CO
Operating Revenues:
Total operating revenues	1,740	1,740	4,716	4,606
Operating Expenses:
Other operations and maintenance	401	406	1,191	1,177
Depreciation and amortization	192	185	570	549
Taxes other than income taxes	97	93	289	284
Total operating expenses	1,179	1,139	3,403	3,203
Operating Income (Loss)	561	601	1,313	1,403
Other Income and (Expense):
Allowance for equity funds used during construction	16	11	43	27
Interest expense, net of amounts capitalized	(82)	(76)	(240)	(229)
Other income (expense), net	9	10	24	35
Total other income and (expense)	(57)	(55)	(173)	(167)
Earnings (Loss) Before Income Taxes	504	546	1,140	1,236
Income taxes	127	216	272	493
Consolidated net income (loss)	377	330	868	743
Dividends on preferred and preference stock of subsidiaries	4	5	11	14
Net Income (Loss)	373	325	857	729
ALABAMA POWER CO | Retail electric revenues
Operating Revenues:
Total operating revenues	1,584	1,595	4,208	4,155
ALABAMA POWER CO | Wholesale electric revenues
Operating Revenues:
Total operating revenues	74	77	213	210
ALABAMA POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	14	18	96	83
ALABAMA POWER CO | Other
Operating Revenues:
Total operating revenues	68	50	199	158
ALABAMA POWER CO | Fuel
Operating Expenses:
Cost of goods and services sold	356	343	1,028	944
ALABAMA POWER CO | Purchased power
Operating Expenses:
Cost of goods and services sold	64	57	176	132
ALABAMA POWER CO | Purchased power, affiliates
Operating Expenses:
Cost of goods and services sold	69	55	149	117
GEORGIA POWER CO
Operating Revenues:
Total operating revenues	2,593	2,546	6,601	6,426
Operating Expenses:
Other operations and maintenance	460	430	1,325	1,248
Depreciation and amortization	232	225	690	669
Taxes other than income taxes	118	112	332	311
Estimated loss on plants under construction	0	0	1,060	0
Total operating expenses	1,602	1,529	5,569	4,305
Operating Income (Loss)	991	1,017	1,032	2,121
Other Income and (Expense):
Allowance for equity funds used during construction			50	29
Interest expense, net of amounts capitalized	(95)	(105)	(303)	(310)
Other income (expense), net	30	22	104	95
Total other income and (expense)	(65)	(83)	(199)	(215)
Earnings (Loss) Before Income Taxes	926	934	833	1,906
Income taxes	262	350	212	705
Consolidated net income (loss)	664	584	621	1,201
Dividends on preferred and preference stock of subsidiaries	0	4	0	13
Net Income (Loss)	664	580	621	1,188
GEORGIA POWER CO | Retail electric revenues
Operating Revenues:
Total operating revenues	2,425	2,402	6,112	5,995
GEORGIA POWER CO | Wholesale electric revenues
Operating Revenues:
Total operating revenues	43	45	123	124
GEORGIA POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	4	6	17	23
GEORGIA POWER CO | Other
Operating Revenues:
Total operating revenues	121	93	349	284
GEORGIA POWER CO | Fuel
Operating Expenses:
Cost of goods and services sold	480	482	1,269	1,297
GEORGIA POWER CO | Purchased power
Operating Expenses:
Cost of goods and services sold	106	119	338	310
GEORGIA POWER CO | Purchased power, affiliates
Operating Expenses:
Cost of goods and services sold	206	161	555	470
GULF POWER CO
Operating Revenues:
Total operating revenues	414	437	1,106	1,144
Operating Expenses:
Other operations and maintenance	82	84	248	260
Depreciation and amortization	48	42	142	95
Taxes other than income taxes	33	33	91	88
Loss on Plant Scherer Unit 3	0	0	0	33
Total operating expenses	339	324	921	915
Operating Income (Loss)	75	113	185	229
Other Income and (Expense):
Interest expense, net of amounts capitalized	(13)	(13)	(39)	(37)
Other income (expense), net	(3)	3	0	7
Total other income and (expense)	(16)	(10)	(39)	(30)
Earnings (Loss) Before Income Taxes	59	103	146	199
Income taxes	(4)	40	(1)	78
Consolidated net income (loss)	63	63	147	121
Dividends on preferred and preference stock of subsidiaries	0	0	0	4
Net Income (Loss)	63	63	147	117
GULF POWER CO | Retail electric revenues
Operating Revenues:
Total operating revenues	341	375	932	972
GULF POWER CO | Wholesale electric revenues
Operating Revenues:
Total operating revenues	15	14	41	44
GULF POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	40	28	83	75
GULF POWER CO | Other
Operating Revenues:
Total operating revenues	18	20	50	53
GULF POWER CO | Fuel
Operating Expenses:
Cost of goods and services sold	132	127	305	323
GULF POWER CO | Purchased power
Operating Expenses:
Cost of goods and services sold	44	38	135	116
MISSISSIPPI POWER CO
Operating Revenues:
Total operating revenues	358	341	956	915
Operating Expenses:
Other operations and maintenance	80	68	222	213
Depreciation and amortization	42	39	126	120
Taxes other than income taxes	28	25	83	77
Estimated loss on plants under construction	1	34	45	3,155
Total operating expenses	278	292	815	3,886
Operating Income (Loss)	80	49	141	(2,971)
Other Income and (Expense):
Allowance for equity funds used during construction	0	1	0	72
Interest expense, net of amounts capitalized	(19)	13	(59)	(23)
Other income (expense), net	0	1	28	4
Total other income and (expense)	(19)	15	(31)	53
Earnings (Loss) Before Income Taxes	61	64	110	(2,918)
Income taxes	14	24	23	(885)
Consolidated net income (loss)	47	40	87	(2,033)
Dividends on preferred and preference stock of subsidiaries	0	0	1	1
Net Income (Loss)	47	40	86	(2,034)
MISSISSIPPI POWER CO | Retail electric revenues
Operating Revenues:
Total operating revenues	254	243	660	665
MISSISSIPPI POWER CO | Wholesale electric revenues
Operating Revenues:
Total operating revenues	65	72	184	196
MISSISSIPPI POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	28	21	81	40
MISSISSIPPI POWER CO | Other
Operating Revenues:
Total operating revenues	11	5	31	14
MISSISSIPPI POWER CO | Fuel
Operating Expenses:
Cost of goods and services sold	116	120	312	301
MISSISSIPPI POWER CO | Purchased power
Operating Expenses:
Cost of goods and services sold	11	6	27	20
SOUTHERN POWER CO
Operating Revenues:
Total operating revenues	635	618	1,699	1,597
Operating Expenses:
Other operations and maintenance	94	83	278	272
Depreciation and amortization	130	131	370	379
Taxes other than income taxes	12	13	36	37
Impairment charges	36	0	155	0
Total operating expenses	499	459	1,487	1,261
Operating Income (Loss)	136	159	212	336
Other Income and (Expense):
Interest expense, net of amounts capitalized	(45)	(47)	(138)	(144)
Other income (expense), net	17	3	22	3
Total other income and (expense)	(28)	(44)	(116)	(141)
Earnings (Loss) Before Income Taxes	108	115	96	195
Income taxes	(38)	(39)	(210)	(129)
Consolidated net income (loss)	146	154	306	324
Net income attributable to noncontrolling interests	54	30	71	48
Net Income (Loss)	92	124	235	276
SOUTHERN POWER CO | Wholesale electric revenues
Operating Revenues:
Total operating revenues	496	510	1,363	1,293
SOUTHERN POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	134	105	326	295
SOUTHERN POWER CO | Other
Operating Revenues:
Total operating revenues	5	3	10	9
SOUTHERN POWER CO | Fuel
Operating Expenses:
Cost of goods and services sold	190	189	511	460
SOUTHERN POWER CO | Purchased power
Operating Expenses:
Cost of goods and services sold	37	43	137	113
SOUTHERN Co GAS
Operating Revenues:
Total operating revenues	492	565	2,861	2,841
Operating Expenses:
Other operations and maintenance	216	206	730	675
Depreciation and amortization	119	125	374	370
Taxes other than income taxes	32	26	157	140
Gain on dispositions, net	(353)	0	(317)	0
Goodwill impairment	0	0	42	0
Total operating expenses	118	498	2,051	2,290
Operating Income (Loss)	374	67	810	551
Other Income and (Expense):
Earnings from equity method investments	34	32	108	100
Interest expense, net of amounts capitalized	(52)	(51)	(170)	(145)
Other income (expense), net	6	19	21	30
Total other income and (expense)	(12)	0	(41)	(15)
Earnings (Loss) Before Income Taxes	362	67	769	536
Income taxes	316	52	475	233
Consolidated net income (loss)	46	15	294	303
Net Income (Loss)	46	15	294	303
SOUTHERN Co GAS | Natural gas
Operating Revenues:
Total operating revenues	487	532	2,829	2,737
Operating Expenses:
Cost of goods and services sold	104	134	1,053	1,085
SOUTHERN Co GAS | Alternative revenue programs
Operating Revenues:
Total operating revenues	5	0	(23)	9
SOUTHERN Co GAS | Other
Operating Revenues:
Total operating revenues	0	33	55	95
Operating Expenses:
Cost of goods and services sold	$ 0	$ 7	$ 12	$ 20