Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Deferred Charges and Other Assets:
Total Assets	$ 75,215	$ 70,923
Common Stockholders' Equity:
Total Stockholders' Equity	21,923	20,926
Southern Company [Member]
Current Assets:
Cash and cash equivalents	1,109	710
Receivables —
Customer accounts receivable	1,432	1,090
Unbilled revenues	488	432
Under recovered regulatory clause revenues	126	136
Other accounts and notes receivable	248	307
Accumulated provision for uncollectible accounts	(19)	(18)
Fossil fuel stock, at average cost	691	930
Materials and supplies, at average cost	1,046	1,039
Vacation pay	177	177
Prepaid expenses	248	665
Deferred income taxes, current	258	506
Other regulatory assets, current	421	346
Other current assets	45	50
Total current assets	6,270	6,370
Property, Plant, and Equipment:
In service	71,929	70,013
Less accumulated provision for depreciation	24,190	24,059
Plant in service, net of depreciation	47,739	45,954
Other utility plant, net	73	211
Nuclear fuel, at amortized cost	869	911
Construction work in progress	9,562	7,792
Total property, plant, and equipment	58,243	54,868
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,473	1,546
Leveraged leases	752	743
Miscellaneous property and investments	489	203
Total other property and investments	2,714	2,492
Deferred Charges and Other Assets:
Deferred charges related to income taxes	1,553	1,510
Unamortized debt issuance expense	203	202
Unamortized loss on reacquired debt	232	243
Other regulatory assets, deferred	4,733	4,334
Income taxes receivable, non-current	444	0
Other deferred charges and assets	823	904
Total deferred charges and other assets	7,988	7,193
Total Assets	75,215	70,923
Current Liabilities:
Securities due within one year	3,313	3,333
Interest-bearing refundable deposits	0	275
Notes payable	1,490	803
Accounts payable —
Accounts payable	1,419	1,593
Customer deposits	400	390
Accrued taxes —
Accrued income taxes	404	151
Other accrued taxes	566	487
Accrued interest	223	295
Accrued vacation pay	223	223
Accrued compensation	462	576
Mirror CWIP	369	271
Other current liabilities	820	570
Total current liabilities	9,689	8,967
Long-term Debt:
Total Long-term Debt	22,326	20,841
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,990	11,568
Deferred credits related to income taxes	183	192
Accumulated deferred investment tax credits	1,004	1,208
Employee benefit obligations	2,408	2,432
Asset retirement obligations	2,952	2,168
Unrecognized tax benefits	369	4
Other cost of removal obligations	1,210	1,215
Other regulatory liabilities, deferred	399	398
Other deferred credits and liabilities	603	590
Total deferred credits and other liabilities	21,118	19,775
Total Liabilities	53,133	49,583
Redeemable Preferred Stock of Subsidiaries	118	375
Redeemable Noncontrolling Interest	41	39
Common Stockholders' Equity:
Common stock	4,558	4,539
Paid-in capital	6,150	5,955
Treasury, at cost	(141)	(26)
Retained earnings (accumulated deficit)	10,233	9,609
Accumulated other comprehensive income (loss)	(136)	(128)
Total common stockholders' equity	20,664	19,949
Preferred and Preference Stock of Subsidiaries	609	756
Noncontrolling Interest	650	221
Total Stockholders' Equity	21,923	20,926
Total Liabilities and Stockholders' Equity	75,215	70,923
Alabama Power [Member]
Current Assets:
Cash and cash equivalents	609	273
Receivables —
Customer accounts receivable	460	345
Unbilled revenues	134	138
Under recovered regulatory clause revenues	67	74
Other accounts and notes receivable	34	23
Affiliated companies	43	37
Accumulated provision for uncollectible accounts	(9)	(9)
Fossil fuel stock, at average cost	199	268
Materials and supplies, at average cost	398	406
Vacation pay	65	65
Prepaid expenses	79	244
Other regulatory assets, current	118	84
Other current assets	9	5
Total current assets	2,206	1,953
Property, Plant, and Equipment:
In service	23,922	23,080
Less accumulated provision for depreciation	8,623	8,522
Plant in service, net of depreciation	15,299	14,558
Nuclear fuel, at amortized cost	325	348
Construction work in progress	1,117	1,006
Total property, plant, and equipment	16,741	15,912
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	69	66
Nuclear decommissioning trusts, at fair value	712	756
Miscellaneous property and investments	91	84
Total other property and investments	872	906
Deferred Charges and Other Assets:
Deferred charges related to income taxes	530	525
Deferred under recovered regulatory clause revenues	66	31
Other regulatory assets, deferred	1,055	1,063
Other deferred charges and assets	163	162
Total deferred charges and other assets	1,814	1,781
Total Assets	21,633	20,552
Current Liabilities:
Securities due within one year	600	454
Accounts payable —
Affiliated accounts payable	272	248
Other accounts payable	272	443
Customer deposits	88	87
Accrued taxes —
Accrued income taxes	105	2
Other accrued taxes	117	37
Accrued interest	67	66
Accrued vacation pay	54	54
Accrued compensation	103	131
Other current liabilities	118	82
Total current liabilities	1,796	1,604
Long-term Debt:
Total Long-term Debt	6,699	6,176
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,965	3,874
Deferred credits related to income taxes	70	72
Accumulated deferred investment tax credits	120	125
Employee benefit obligations	319	326
Asset retirement obligations	1,288	829
Other cost of removal obligations	742	744
Other regulatory liabilities, deferred	152	239
Deferred over recovered regulatory clause revenues	128	47
Other deferred credits and liabilities	73	79
Total deferred credits and other liabilities	6,857	6,335
Total Liabilities	15,352	14,115
Redeemable Preferred Stock	85	342
Preference Stock	196	343
Common Stockholders' Equity:
Common stock	1,222	1,222
Paid-in capital	2,328	2,304
Retained earnings (accumulated deficit)	2,483	2,255
Accumulated other comprehensive income (loss)	(33)	(29)
Total common stockholders' equity	6,000	5,752
Total Liabilities and Stockholders' Equity	21,633	20,552
Georgia Power [Member]
Current Assets:
Cash and cash equivalents	85	24
Receivables —
Customer accounts receivable	758	553
Unbilled revenues	243	201
Joint owner accounts receivable	52	121
Other accounts and notes receivable	47	61
Affiliated companies	22	18
Accumulated provision for uncollectible accounts	(7)	(6)
Fossil fuel stock, at average cost	298	439
Materials and supplies, at average cost	439	438
Vacation pay	90	91
Prepaid income taxes	24	278
Other regulatory assets, current	124	136
Other current assets	94	74
Total current assets	2,269	2,428
Property, Plant, and Equipment:
In service	31,546	31,083
Less accumulated provision for depreciation	11,046	11,222
Plant in service, net of depreciation	20,500	19,861
Other utility plant, net	10	211
Nuclear fuel, at amortized cost	544	563
Construction work in progress	4,390	4,031
Total property, plant, and equipment	25,444	24,666
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	62	58
Nuclear decommissioning trusts, at fair value	761	789
Miscellaneous property and investments	38	38
Total other property and investments	861	885
Deferred Charges and Other Assets:
Deferred charges related to income taxes	678	698
Deferred under recovered regulatory clause revenues	0	197
Other regulatory assets, deferred	2,075	1,753
Other deferred charges and assets	399	403
Total deferred charges and other assets	3,152	3,051
Total Assets	31,726	31,030
Current Liabilities:
Securities due within one year	1,362	1,154
Notes payable	130	156
Accounts payable —
Affiliated accounts payable	444	451
Other accounts payable	515	555
Customer deposits	260	253
Accrued taxes —
Accrued income taxes	75	1
Other accrued taxes	311	332
Accrued interest	99	96
Accrued vacation pay	62	63
Accrued compensation	120	153
Other current liabilities	345	256
Total current liabilities	3,723	3,470
Long-term Debt:
Total Long-term Debt	8,709	8,683
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	5,493	5,507
Deferred credits related to income taxes	101	106
Accumulated deferred investment tax credits	188	196
Employee benefit obligations	893	903
Asset retirement obligations	1,332	1,223
Other deferred credits and liabilities	266	255
Total deferred credits and other liabilities	8,273	8,190
Total Liabilities	20,705	20,343
Redeemable Preferred Stock	45	45
Preference Stock	221	221
Common Stockholders' Equity:
Common stock	398	398
Paid-in capital	6,251	6,196
Retained earnings (accumulated deficit)	4,123	3,835
Accumulated other comprehensive income (loss)	(17)	(8)
Total common stockholders' equity	10,755	10,421
Total Liabilities and Stockholders' Equity	31,726	31,030
Gulf Power [Member]
Current Assets:
Cash and cash equivalents	41	39
Receivables —
Customer accounts receivable	100	73
Unbilled revenues	68	58
Under recovered regulatory clause revenues	17	57
Other accounts and notes receivable	9	8
Affiliated companies	4	10
Accumulated provision for uncollectible accounts	(2)	(2)
Fossil fuel stock, at average cost	84	101
Materials and supplies, at average cost	57	56
Prepaid expenses	13	40
Other regulatory assets, current	81	74
Other current assets	1	2
Total current assets	473	516
Property, Plant, and Equipment:
In service	4,640	4,495
Less accumulated provision for depreciation	1,273	1,296
Plant in service, net of depreciation	3,367	3,199
Other utility plant, net	64	0
Construction work in progress	407	465
Total property, plant, and equipment	3,838	3,664
Other Property and Investments:
Total other property and investments	15	15
Deferred Charges and Other Assets:
Deferred charges related to income taxes	61	56
Other regulatory assets, deferred	430	416
Other deferred charges and assets	44	41
Total deferred charges and other assets	535	513
Total Assets	4,861	4,708
Current Liabilities:
Notes payable	76	110
Accounts payable —
Affiliated accounts payable	65	87
Other accounts payable	40	56
Customer deposits	36	35
Accrued taxes —
Accrued income taxes	22	0
Other accrued taxes	33	9
Accrued interest	20	11
Accrued compensation	20	23
Deferred capacity expense, current	22	22
Liabilities from risk management activities	41	37
Other current liabilities	44	23
Total current liabilities	419	413
Long-term Debt:
Total Long-term Debt	1,310	1,370
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	870	800
Employee benefit obligations	120	121
Other cost of removal obligations	226	235
Other regulatory liabilities, deferred	49	49
Deferred capacity expense	147	163
Other deferred credits and liabilities	216	101
Total deferred credits and other liabilities	1,628	1,469
Total Liabilities	3,357	3,252
Preference Stock	147	147
Common Stockholders' Equity:
Common stock	503	483
Paid-in capital	564	560
Retained earnings (accumulated deficit)	290	267
Accumulated other comprehensive income (loss)	0	(1)
Total common stockholders' equity	1,357	1,309
Total Liabilities and Stockholders' Equity	4,861	4,708
Mississippi Power [Member]
Current Assets:
Cash and cash equivalents	96	133
Receivables —
Customer accounts receivable	51	43
Unbilled revenues	42	35
Other accounts and notes receivable	11	11
Affiliated companies	31	51
Accumulated provision for uncollectible accounts	(1)	(1)
Fossil fuel stock, at average cost	95	100
Materials and supplies, at average cost	72	62
Prepaid income taxes	183	191
Other regulatory assets, current	119	73
Other current assets	10	6
Total current assets	709	704
Property, Plant, and Equipment:
In service	4,475	4,378
Less accumulated provision for depreciation	1,215	1,173
Plant in service, net of depreciation	3,260	3,205
Construction work in progress	2,596	2,161
Total property, plant, and equipment	5,856	5,366
Other Property and Investments:
Total other property and investments	6	5
Deferred Charges and Other Assets:
Deferred charges related to income taxes	278	226
Other regulatory assets, deferred	460	385
Income taxes receivable, non-current	544	0
Other deferred charges and assets	60	71
Total deferred charges and other assets	1,342	682
Total Assets	7,913	6,757
Current Liabilities:
Securities due within one year	429	778
Interest-bearing refundable deposits	0	275
Notes payable	500	0
Accounts payable —
Affiliated accounts payable	91	86
Other accounts payable	109	178
Accrued taxes —
Accrued income taxes	288	142
Other accrued taxes	67	84
Accrued interest	15	76
Accrued compensation	18	26
Over recovered regulatory clause liabilities	60	1
Mirror CWIP	369	271
Other current liabilities	87	61
Total current liabilities	2,033	1,978
Long-term Debt:
Long-term debt, affiliated	301	0
Long-term debt, non-affiliated	1,621	1,630
Total Long-term Debt	1,922	1,630
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	674	285
Accumulated deferred investment tax credits	5	283
Employee benefit obligations	147	148
Asset retirement obligations	150	48
Unrecognized tax benefits	361	2
Other cost of removal obligations	171	166
Other regulatory liabilities, deferred	66	64
Other deferred credits and liabilities	48	36
Total deferred credits and other liabilities	1,622	1,032
Total Liabilities	5,577	4,640
Redeemable Preferred Stock	33	33
Common Stockholders' Equity:
Common stock	38	38
Paid-in capital	2,767	2,612
Retained earnings (accumulated deficit)	(496)	(559)
Accumulated other comprehensive income (loss)	(6)	(7)
Total common stockholders' equity	2,303	2,084
Total Liabilities and Stockholders' Equity	7,913	6,757
Southern Power [Member]
Current Assets:
Cash and cash equivalents	161	75
Receivables —
Customer accounts receivable	100	77
Other accounts and notes receivable	35	15
Affiliated companies	50	34
Fossil fuel stock, at average cost	16	22
Materials and supplies, at average cost	60	58
Prepaid income taxes	136	19
Deferred income taxes, current	0	306
Other current assets	19	21
Total current assets	577	627
Property, Plant, and Equipment:
In service	6,049	5,657
Less accumulated provision for depreciation	1,189	1,035
Plant in service, net of depreciation	4,860	4,622
Construction work in progress	977	11
Total property, plant, and equipment	5,837	4,633
Other Property and Investments:
Goodwill	2	2
Other intangible assets, net of amortization of $11 and $8 at September 30, 2015 and December 31, 2014, respectively	318	47
Total other property and investments	320	49
Deferred Charges and Other Assets:
Prepaid long-term service agreements	157	124
Other deferred charges and assets -- affiliated	3	5
Other deferred charges and assets	146	112
Total deferred charges and other assets	306	241
Total Assets	7,040	5,550
Current Liabilities:
Securities due within one year	400	525
Notes payable	213	195
Accounts payable —
Affiliated accounts payable	69	78
Other accounts payable	161	30
Accrued taxes —
Accrued income taxes	3	72
Accrued interest	14	30
Other current liabilities	56	17
Total current liabilities	916	947
Long-term Debt:
Total Long-term Debt	1,742	1,095
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	779	863
Accumulated deferred investment tax credits	688	601
Accrued income taxes, non-current	100	0
Deferred capacity revenues -- affiliated	39	15
Other deferred credits and liabilities — affiliated	0	1
Other deferred credits and liabilities	25	18
Total deferred credits and other liabilities	1,631	1,498
Total Liabilities	4,289	3,540
Redeemable Noncontrolling Interest	41	39
Common Stockholders' Equity:
Common stock	0	0
Paid-in capital	1,401	1,176
Retained earnings (accumulated deficit)	657	573
Accumulated other comprehensive income (loss)	3	3
Total common stockholders' equity	2,061	1,752
Noncontrolling Interest, Total	649	219
Total Stockholders' Equity	2,710	1,971
Total Liabilities and Stockholders' Equity	$ 7,040	$ 5,550