Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Deferred Charges and Other Assets:
Total Assets	$ 71,610	$ 70,923
Common Stockholders' Equity:
Total Stockholders' Equity	20,994	20,926
Southern Company [Member]
Current Assets:
Cash and cash equivalents	1,112	710
Receivables --
Customer accounts receivable	1,117	1,090
Unbilled revenues	374	432
Under recovered regulatory clause revenues	159	136
Other accounts and notes receivable	241	307
Accumulated provision for uncollectible accounts	(19)	(18)
Fossil fuel stock, at average cost	855	930
Materials and supplies, at average cost	1,050	1,039
Vacation pay	178	177
Prepaid expenses	299	665
Deferred income taxes, current	578	506
Other regulatory assets, current	363	346
Other current assets	65	50
Total current assets	6,372	6,370
Property, Plant, and Equipment:
In service	70,279	70,013
Less accumulated provision for depreciation	24,307	24,059
Plant in service, net of depreciation	45,972	45,954
Other utility plant, net	275	211
Nuclear fuel, at amortized cost	914	911
Construction work in progress	8,314	7,792
Total property, plant, and equipment	55,475	54,868
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,574	1,546
Leveraged leases	749	743
Miscellaneous property and investments	204	203
Total other property and investments	2,527	2,492
Deferred Charges and Other Assets:
Deferred charges related to income taxes	1,527	1,510
Unamortized debt issuance expense	200	202
Unamortized loss on reacquired debt	239	243
Other regulatory assets, deferred	4,462	4,334
Other deferred charges and assets	808	904
Total deferred charges and other assets	7,236	7,193
Total Assets	71,610	70,923
Current Liabilities:
Securities due within one year	3,306	3,333
Interest-bearing refundable deposit	275	275
Notes payable	1,679	803
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accounts payable	1,289	1,593
Customer deposits	395	390
Accrued taxes --
Accrued income taxes	198	151
Other accrued taxes	248	487
Accrued interest	286	295
Accrued vacation pay	222	223
Accrued compensation	186	576
Dividends on preferred and preference stock of subsidiaries	17
Mirror CWIP	311	271
Other current liabilities	790	570
Total current liabilities	9,185	8,967
Long-term Debt	21,093	20,841
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,706	11,568
Deferred credits related to income taxes	185	192
Accumulated deferred investment tax credits	1,198	1,208
Employee benefit obligations	2,416	2,432
Asset retirement obligations	2,151	2,168
Other cost of removal obligations	1,209	1,215
Other regulatory liabilities, deferred	439	398
Other deferred credits and liabilities	619	594
Total deferred credits and other liabilities	19,923	19,775
Total Liabilities	50,201	49,583
Redeemable Preferred Stock of Subsidiaries	375	375
Redeemable Noncontrolling Interest	40	39
Common Stockholders' Equity:
Common stock	4,555	4,539
Paid-in capital	6,108	5,955
Treasury, at cost	(142)	(26)
Retained earnings (accumulated deficit)	9,639	9,609
Accumulated other comprehensive income (loss)	(143)	(128)
Total common stockholders' equity	20,017	19,949
Preferred and Preference Stock of Subsidiaries	756	756
Noncontrolling Interest	221	221
Total Stockholders' Equity	20,994	20,926
Total Liabilities and Stockholders' Equity	71,610	70,923
Alabama Power [Member]
Current Assets:
Cash and cash equivalents	395	273
Receivables --
Customer accounts receivable	374	345
Unbilled revenues	115	138
Under recovered regulatory clause revenues	16	74
Other accounts and notes receivable	24	23
Affiliated companies	36	37
Accumulated provision for uncollectible accounts	(10)	(9)
Fossil fuel stock, at average cost	268	268
Materials and supplies, at average cost	410	406
Vacation pay	66	65
Prepaid expenses	134	244
Other regulatory assets, current	91	84
Other current assets	4	5
Total current assets	1,923	1,953
Property, Plant, and Equipment:
In service	23,254	23,080
Less accumulated provision for depreciation	8,627	8,522
Plant in service, net of depreciation	14,627	14,558
Nuclear fuel, at amortized cost	359	348
Construction work in progress	1,089	1,006
Total property, plant, and equipment	16,075	15,912
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	67	66
Nuclear decommissioning trusts, at fair value	770	756
Miscellaneous property and investments	85	84
Total other property and investments	922	906
Deferred Charges and Other Assets:
Deferred charges related to income taxes	523	525
Deferred under recovered regulatory clause revenues	87	31
Other regulatory assets, deferred	1,065	1,063
Other deferred charges and assets	161	162
Total deferred charges and other assets	1,836	1,781
Total Assets	20,756	20,552
Current Liabilities:
Securities due within one year	734	454
Accounts Payable and Accrued Liabilities, Current [Abstract]
Affiliated accounts payable	225	248
Other accounts payable	273	443
Customer deposits	88	87
Accrued taxes --
Accrued income taxes	37	2
Other accrued taxes	59	37
Accrued interest	59	66
Accrued vacation pay	54	54
Accrued compensation	44	131
Other regulatory liabilities, current	2	2
Dividends on preferred and preference stock of subsidiaries	10
Other current liabilities	114	80
Total current liabilities	1,689	1,604
Long-term Debt	6,193	6,176
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,890	3,874
Deferred credits related to income taxes	71	72
Accumulated deferred investment tax credits	123	125
Employee benefit obligations	322	326
Asset retirement obligations	840	829
Other cost of removal obligations	743	744
Other regulatory liabilities, deferred	242	239
Deferred over recovered regulatory clause revenues	81	47
Other deferred credits and liabilities	88	79
Total deferred credits and other liabilities	6,400	6,335
Total Liabilities	14,282	14,115
Redeemable Preferred Stock	342	342
Preference Stock	343	343
Common Stockholders' Equity:
Common stock	1,222	1,222
Paid-in capital	2,318	2,304
Retained earnings (accumulated deficit)	2,281	2,255
Accumulated other comprehensive income (loss)	(32)	(29)
Total common stockholders' equity	5,789	5,752
Total Liabilities and Stockholders' Equity	20,756	20,552
Georgia Power [Member]
Current Assets:
Cash and cash equivalents	413	24
Receivables --
Customer accounts receivable	642	553
Unbilled revenues	174	201
Joint owner accounts receivable	47	121
Other accounts and notes receivable	70	61
Affiliated companies	16	18
Accumulated provision for uncollectible accounts	(7)	(6)
Fossil fuel stock, at average cost	372	439
Materials and supplies, at average cost	443	438
Vacation pay	91	91
Prepaid income taxes	86	278
Other regulatory assets, current	142	136
Other current assets	85	74
Total current assets	2,574	2,428
Property, Plant, and Equipment:
In service	31,425	31,083
Less accumulated provision for depreciation	11,326	11,222
Plant in service, net of depreciation	20,099	19,861
Other utility plant, net	197	211
Nuclear fuel, at amortized cost	555	563
Construction work in progress	4,193	4,031
Total property, plant, and equipment	25,044	24,666
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	60	58
Nuclear decommissioning trusts, at fair value	804	789
Miscellaneous property and investments	37	38
Total other property and investments	901	885
Deferred Charges and Other Assets:
Deferred charges related to income taxes	696	698
Deferred under recovered regulatory clause revenues	62	197
Other regulatory assets, deferred	1,796	1,753
Other deferred charges and assets	443	403
Total deferred charges and other assets	2,997	3,051
Total Assets	31,516	31,030
Current Liabilities:
Securities due within one year	1,600	1,154
Notes payable	840	156
Accounts Payable and Accrued Liabilities, Current [Abstract]
Affiliated accounts payable	364	451
Other accounts payable	469	555
Customer deposits	256	253
Accrued taxes --
Other accrued taxes	116	332
Accrued interest	100	96
Accrued vacation pay	62	63
Accrued compensation	54	153
Dividends on preferred and preference stock of subsidiaries	4
Liabilities from risk management activities	52	32
Other current liabilities	388	225
Total current liabilities	4,301	3,470
Long-term Debt	8,393	8,683
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	5,471	5,507
Deferred credits related to income taxes	104	106
Accumulated deferred investment tax credits	193	196
Employee benefit obligations	891	903
Asset retirement obligations	1,223	1,223
Other deferred credits and liabilities	268	255
Total deferred credits and other liabilities	8,150	8,190
Total Liabilities	20,844	20,343
Redeemable Preferred Stock	45	45
Preference Stock	221	221
Common Stockholders' Equity:
Common stock	398	398
Paid-in capital	6,218	6,196
Retained earnings (accumulated deficit)	3,812	3,835
Accumulated other comprehensive income (loss)	(22)	(8)
Total common stockholders' equity	10,406	10,421
Total Liabilities and Stockholders' Equity	31,516	31,030
Gulf Power [Member]
Current Assets:
Cash and cash equivalents	55	39
Receivables --
Customer accounts receivable	79	73
Unbilled revenues	52	58
Under recovered regulatory clause revenues	53	57
Other accounts and notes receivable	9	8
Affiliated companies	1	10
Accumulated provision for uncollectible accounts	(2)	(2)
Fossil fuel stock, at average cost	104	101
Materials and supplies, at average cost	54	56
Prepaid expenses	38	40
Other regulatory assets, current	77	74
Other current assets	2	2
Total current assets	522	516
Property, Plant, and Equipment:
In service	4,405	4,495
Less accumulated provision for depreciation	1,236	1,296
Plant in service, net of depreciation	3,169	3,199
Other utility plant, net	79	0
Construction work in progress	474	465
Total property, plant, and equipment	3,722	3,664
Other Property and Investments:
Total other property and investments	15	15
Deferred Charges and Other Assets:
Deferred charges related to income taxes	59	56
Other regulatory assets, deferred	423	416
Other deferred charges and assets	37	41
Total deferred charges and other assets	519	513
Total Assets	4,778	4,708
Current Liabilities:
Securities due within one year	23	0
Notes payable	150	110
Accounts Payable and Accrued Liabilities, Current [Abstract]
Affiliated accounts payable	68	87
Other accounts payable	49	56
Customer deposits	35	35
Accrued taxes --
Other accrued taxes	14	9
Accrued interest	21	11
Accrued compensation	7	23
Deferred capacity expense, current	22	22
Dividends on preferred and preference stock of subsidiaries	2
Liabilities from risk management activities	37	37
Other current liabilities	24	23
Total current liabilities	450	413
Long-term Debt	1,347	1,370
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	836	800
Employee benefit obligations	120	121
Other cost of removal obligations	218	235
Other regulatory liabilities, deferred	45	49
Deferred capacity expense	158	163
Other deferred credits and liabilities	120	101
Total deferred credits and other liabilities	1,497	1,469
Total Liabilities	3,294	3,252
Preference Stock	147	147
Common Stockholders' Equity:
Common stock	503	483
Paid-in capital	563	560
Retained earnings (accumulated deficit)	272	267
Accumulated other comprehensive income (loss)	(1)	(1)
Total common stockholders' equity	1,337	1,309
Total Liabilities and Stockholders' Equity	4,778	4,708
Mississippi Power [Member]
Current Assets:
Cash and cash equivalents	134	133
Receivables --
Customer accounts receivable	38	43
Unbilled revenues	33	35
Other accounts and notes receivable	13	11
Affiliated companies	40	51
Accumulated provision for uncollectible accounts	(1)	(1)
Fossil fuel stock, at average cost	96	100
Materials and supplies, at average cost	64	62
Prepaid income taxes	162	191
Other regulatory assets, current	74	73
Other current assets	6	6
Total current assets	659	704
Property, Plant, and Equipment:
In service	4,396	4,378
Less accumulated provision for depreciation	1,194	1,173
Plant in service, net of depreciation	3,202	3,205
Construction work in progress	2,361	2,161
Total property, plant, and equipment	5,563	5,366
Other Property and Investments:
Total other property and investments	6	5
Deferred Charges and Other Assets:
Deferred charges related to income taxes	243	226
Other regulatory assets, deferred	419	385
Other deferred charges and assets	57	71
Total deferred charges and other assets	719	682
Total Assets	6,947	6,757
Current Liabilities:
Securities due within one year	3	778
Interest-bearing refundable deposit	275	275
Notes payable	30	0
Accounts Payable and Accrued Liabilities, Current [Abstract]
Affiliated accounts payable	80	86
Other accounts payable	148	178
Accrued taxes --
Accrued income taxes	185	142
Other accrued taxes	29	84
Accrued interest	86	76
Accrued compensation	6	26
Dividends on preferred and preference stock of subsidiaries	0
Over recovered regulatory clause liabilities	23	1
Mirror CWIP	311	271
Other current liabilities	61	61
Total current liabilities	1,237	1,978
Long-term Debt	2,328	1,630
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	397	285
Accumulated deferred investment tax credits	282	283
Employee benefit obligations	148	148
Asset retirement obligations	49	48
Other cost of removal obligations	168	166
Other regulatory liabilities, deferred	65	64
Other deferred credits and liabilities	43	38
Total deferred credits and other liabilities	1,152	1,032
Total Liabilities	4,717	4,640
Redeemable Preferred Stock	33	33
Common Stockholders' Equity:
Common stock	38	38
Paid-in capital	2,690	2,612
Retained earnings (accumulated deficit)	(524)	(559)
Accumulated other comprehensive income (loss)	(7)	(7)
Total common stockholders' equity	2,197	2,084
Total Liabilities and Stockholders' Equity	6,947	6,757
Southern Power [Member]
Current Assets:
Cash and cash equivalents	23	75
Receivables --
Customer accounts receivable	71	77
Other accounts and notes receivable	14	15
Affiliated companies	37	34
Fossil fuel stock, at average cost	16	22
Materials and supplies, at average cost	59	58
Prepaid service agreements - current	10	8
Prepaid expenses	10	8
Deferred income taxes, current	379	306
Assets from risk management activities	0	5
Prepaid income taxes	21	19
Total current assets	640	627
Property, Plant, and Equipment:
In service	5,658	5,657
Less accumulated provision for depreciation	1,093	1,035
Plant in service, net of depreciation	4,565	4,622
Construction work in progress	48	11
Total property, plant, and equipment	4,613	4,633
Other Property and Investments:
Goodwill	2	2
Other intangible assets, net of amortization of $9 and $8 at March 31, 2015 and December 31, 2014, respectively	46	47
Total other property and investments	48	49
Deferred Charges and Other Assets:
Prepaid long-term service agreements	137	124
Other deferred charges and assets -- affiliated	13	5
Other deferred charges and assets	113	112
Total deferred charges and other assets	263	241
Total Assets	5,564	5,550
Current Liabilities:
Securities due within one year	525	525
Notes payable	233	195
Accounts Payable and Accrued Liabilities, Current [Abstract]
Affiliated accounts payable	69	78
Other accounts payable	32	30
Accrued taxes --
Accrued income taxes	65	72
Accrued interest	15	30
Other current liabilities	19	17
Total current liabilities	958	947
Long-term Debt	1,095	1,095
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	882	863
Accumulated deferred investment tax credits	596	601
Deferred capacity revenues -- affiliated	5	15
Other deferred credits and liabilities — affiliated	0	1
Other deferred credits and liabilities	16	18
Total deferred credits and other liabilities	1,499	1,498
Total Liabilities	3,552	3,540
Redeemable Noncontrolling Interest	40	39
Common Stockholders' Equity:
Common stock	0	0
Paid-in capital	1,176	1,176
Retained earnings (accumulated deficit)	574	573
Accumulated other comprehensive income (loss)	3	3
Total common stockholders' equity	1,753	1,752
Noncontrolling Interest, Total	219	219
Total Stockholders' Equity	1,972	1,971
Total Liabilities and Stockholders' Equity	$ 5,564	$ 5,550