Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 1,404	$ 710
Receivables --
Customer accounts receivable	1,058	1,090
Unbilled revenues	397	432
Under recovered regulatory clause revenues	63	136
Other accounts and notes receivable	398	307
Accumulated provision for uncollectible accounts	(13)	(18)
Income taxes receivable, current	144	0
Fossil fuel stock, at average cost	868	930
Materials and supplies, at average cost	1,061	1,039
Vacation pay	178	177
Prepaid expenses	495	665
Other regulatory assets, current	402	346
Other current assets	71	50
Total current assets	6,526	5,864
Property, Plant, and Equipment:
In service	75,118	70,013
Less accumulated depreciation	24,253	24,059
Plant in service, net of depreciation	50,865	45,954
Other utility plant, net	233	211
Nuclear fuel, at amortized cost	934	911
Construction work in progress	9,082	7,792
Total property, plant, and equipment	61,114	54,868
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,512	1,546
Leveraged leases	755	743
Miscellaneous property and investments	485	203
Total other property and investments	2,752	2,492
Deferred Charges and Other Assets:
Deferred charges related to income taxes	1,560	1,510
Unamortized loss on reacquired debt	227	243
Other regulatory assets, deferred	4,989	4,334
Income taxes receivable, non-current	413	0
Other deferred charges and assets	737	922
Total deferred charges and other assets	7,926	7,009
Total Assets	78,318	70,233
Current Liabilities:
Securities due within one year	2,674	3,329
Interest-bearing refundable deposits	0	275
Notes payable	1,376	803
Accounts payable	1,905	1,593
Customer deposits	404	390
Accrued taxes --
Accrued income taxes	19	149
Other accrued taxes	484	487
Accrued interest	249	295
Accrued vacation pay	228	223
Accrued compensation	549	576
Asset retirement obligations, current	217	32
Liabilities from risk management activities	156	138
Other regulatory liabilities, current	278	26
Mirror CWIP	0	271
Other current liabilities	590	374
Total current liabilities	9,129	8,961
Senior notes -
Unamortized Debt Issuance Expense	241	202
Long-term Debt	24,688	20,644
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	12,322	11,082
Deferred credits related to income taxes	187	192
Accumulated deferred investment tax credits	1,219	1,208
Employee benefit obligations	2,582	2,432
Asset retirement obligations	3,542	2,168
Unrecognized tax benefits	370	4
Other cost of removal obligations	1,162	1,215
Other regulatory liabilities, deferred	254	398
Other deferred credits and liabilities	720	589
Total deferred credits and other liabilities	22,358	19,288
Total Liabilities	56,175	48,893
Redeemable Preferred Stock of Subsidiaries	118	375
Redeemable Noncontrolling Interests	43	39
Common Stockholders' Equity:
Common stock	4,572	4,539
Paid-in capital	6,282	5,955
Retained earnings	10,010	9,609
Accumulated other comprehensive loss	(130)	(128)
Common Stockholders' Equity	20,592	19,949
Stockholders' Equity Attributable to Noncontrolling Interest	1,390	977
Total stockholders' equity	21,982	20,926
Total Liabilities and Stockholders' Equity	$ 78,318	$ 70,233
Commitments and Contingent Matters
Alabama Power [Member]
Current Assets:
Cash and cash equivalents	$ 194	$ 273
Receivables --
Customer accounts receivable	332	345
Unbilled revenues	119	138
Under recovered regulatory clause revenues	43	74
Other accounts and notes receivable	20	23
Affiliated companies	50	37
Accumulated provision for uncollectible accounts	(10)	(9)
Income taxes receivable, current	142	0
Fossil fuel stock, at average cost	239	268
Materials and supplies, at average cost	398	406
Vacation pay	66	65
Prepaid expenses	83	224
Other regulatory assets, current	115	84
Other current assets	10	6
Total current assets	1,801	1,934
Property, Plant, and Equipment:
In service	24,750	23,080
Less accumulated depreciation	8,736	8,522
Plant in service, net of depreciation	16,014	14,558
Nuclear fuel, at amortized cost	363	348
Construction work in progress	801	1,006
Total property, plant, and equipment	17,178	15,912
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	71	66
Nuclear decommissioning trusts, at fair value	737	756
Miscellaneous property and investments	96	84
Total other property and investments	904	906
Deferred Charges and Other Assets:
Deferred charges related to income taxes	522	525
Deferred under recovered regulatory clause revenues	99	31
Other regulatory assets, deferred	1,114	1,063
Other deferred charges and assets	103	122
Total deferred charges and other assets	1,838	1,741
Total Assets	21,721	20,493
Current Liabilities:
Securities due within one year	200	454
Notes payable	0	0
Accounts payable - Affiliated	278	248
Accounts payable - Other	410	443
Customer deposits	88	87
Accrued taxes --
Accrued income taxes	38	37
Accrued interest	73	66
Accrued vacation pay	55	54
Accrued compensation	119	131
Liabilities from risk management activities	55	40
Other regulatory liabilities, current	240	2
Other current liabilities	39	40
Total current liabilities	1,595	1,602
Senior notes -
Unamortized debt premium (discount), net	(9)	(7)
Unamortized Debt Issuance Expense	45	39
Long-term Debt	6,654	6,137
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	4,241	3,857
Deferred credits related to income taxes	70	72
Accumulated deferred investment tax credits	118	125
Employee benefit obligations	388	326
Asset retirement obligations	1,448	829
Other cost of removal obligations	722	744
Other regulatory liabilities, deferred	136	239
Deferred over recovered regulatory clause revenues	0	47
Other deferred credits and liabilities	76	78
Total deferred credits and other liabilities	7,199	6,317
Total Liabilities	15,448	14,056
Redeemable Preferred Stock of Subsidiaries	85	342
Redeemable Preferred Stock	85	342
Preference Stock	196	343
Common Stockholders' Equity:
Common stock	1,222	1,222
Paid-in capital	2,341	2,304
Retained earnings	2,461	2,255
Accumulated other comprehensive loss	(32)	(29)
Common Stockholders' Equity	5,992	5,752
Total stockholders' equity	5,992	5,752
Total Liabilities and Stockholders' Equity	$ 21,721	$ 20,493
Commitments and Contingent Matters
Georgia Power [Member]
Current Assets:
Cash and cash equivalents	$ 67	$ 24
Receivables --
Customer accounts receivable	541	553
Unbilled revenues	188	201
Joint owner accounts receivable	227	121
Other accounts and notes receivable	57	61
Affiliated companies	18	18
Accumulated provision for uncollectible accounts	(2)	(6)
Income taxes receivable, current	114	0
Fossil fuel stock, at average cost	402	439
Materials and supplies, at average cost	449	438
Vacation pay	91	91
Prepaid income taxes	156	244
Other regulatory assets, current	123	136
Other current assets	92	74
Total current assets	2,523	2,394
Property, Plant, and Equipment:
In service	31,841	31,083
Less accumulated depreciation	10,903	11,222
Plant in service, net of depreciation	20,938	19,861
Other utility plant, net	171	211
Nuclear fuel, at amortized cost	572	563
Construction work in progress	4,775	4,031
Total property, plant, and equipment	26,456	24,666
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	64	58
Nuclear decommissioning trusts, at fair value	775	789
Miscellaneous property and investments	43	38
Total other property and investments	882	885
Deferred Charges and Other Assets:
Deferred charges related to income taxes	679	698
Deferred under recovered regulatory clause revenues	0	197
Other regulatory assets, deferred	2,152	1,753
Other deferred charges and assets	173	279
Total deferred charges and other assets	3,004	2,927
Total Assets	32,865	30,872
Current Liabilities:
Securities due within one year	712	1,150
Notes payable	158	156
Accounts payable - Affiliated	411	451
Accounts payable - Other	750	555
Customer deposits	264	253
Accrued taxes --
Accrued income taxes	12	0
Other accrued taxes	325	332
Accrued interest	99	96
Accrued vacation pay	62	63
Accrued compensation	142	153
Asset retirement obligations, current	179	32
Liabilities from risk management activities	12	32
Other regulatory liabilities, current	16	21
Over recovered regulatory clause revenues, current	10	0
Other current liabilities	143	172
Total current liabilities	3,295	3,466
Senior notes -
Unamortized debt premium (discount), net	(10)	(11)
Unamortized Debt Issuance Expense	118	124
Long-term Debt	9,616	8,563
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	5,627	5,474
Deferred credits related to income taxes	105	106
Accumulated deferred investment tax credits	204	196
Employee benefit obligations	949	903
Deferred capacity expense	203	167
Asset retirement obligations	1,737	1,223
Other cost of removal obligations	16	46
Other deferred credits and liabilities	331	208
Total deferred credits and other liabilities	8,969	8,156
Total Liabilities	21,880	20,185
Redeemable Preferred Stock	45	45
Preference Stock	221	221
Common Stockholders' Equity:
Common stock	398	398
Paid-in capital	6,275	6,196
Retained earnings	4,061	3,835
Accumulated other comprehensive loss	(15)	(8)
Common Stockholders' Equity	10,719	10,421
Total stockholders' equity	10,719	10,421
Total Liabilities and Stockholders' Equity	$ 32,865	$ 30,872
Commitments and Contingent Matters
Gulf Power [Member]
Current Assets:
Cash and cash equivalents	$ 74	$ 39
Receivables --
Customer accounts receivable	76	73
Unbilled revenues	54	58
Under recovered regulatory clause revenues	20	57
Other accounts and notes receivable	9	8
Affiliated companies	1	10
Accumulated provision for uncollectible accounts	(1)	(2)
Income taxes receivable, current	27	0
Fossil fuel stock, at average cost	108	101
Materials and supplies, at average cost	56	56
Prepaid expenses	8	37
Other regulatory assets, current	90	74
Other current assets	14	2
Total current assets	536	513
Property, Plant, and Equipment:
In service	5,045	4,495
Less accumulated depreciation	1,296	1,296
Plant in service, net of depreciation	3,749	3,199
Other utility plant, net	62	0
Construction work in progress	48	465
Total property, plant, and equipment	3,859	3,664
Other Property and Investments:
Total other property and investments	4	15
Deferred Charges and Other Assets:
Deferred charges related to income taxes	61	56
Other regulatory assets, deferred	427	416
Other deferred charges and assets	33	33
Total deferred charges and other assets	521	505
Total Assets	4,920	4,697
Current Liabilities:
Securities due within one year	110	0
Notes payable	142	110
Accounts payable - Affiliated	55	87
Accounts payable - Other	44	56
Customer deposits	36	35
Accrued taxes --
Accrued income taxes	4	0
Other accrued taxes	9	9
Accrued interest	9	11
Accrued compensation	25	23
Deferred capacity expense, current	22	22
Liabilities from risk management activities	49	37
Other regulatory liabilities, current	22	1
Other current liabilities	40	22
Total current liabilities	567	413
Senior notes -
Unamortized debt premium (discount), net	(8)	(9)
Unamortized Debt Issuance Expense	8	8
Long-term Debt	1,193	1,362
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	893	797
Employee benefit obligations	129	121
Deferred capacity expense	141	163
Asset retirement obligations	113	17
Other cost of removal obligations	233	235
Other regulatory liabilities, deferred	47	48
Other deferred credits and liabilities	102	85
Total deferred credits and other liabilities	1,658	1,466
Total Liabilities	3,418	3,241
Preference Stock	147	147
Common Stockholders' Equity:
Common stock	503	483
Paid-in capital	567	560
Retained earnings	285	267
Accumulated other comprehensive loss	0	(1)
Common Stockholders' Equity	1,355	1,309
Total stockholders' equity	1,355	1,309
Total Liabilities and Stockholders' Equity	$ 4,920	$ 4,697
Commitments and Contingent Matters
Mississippi Power [Member]
Current Assets:
Cash and cash equivalents	$ 98	$ 133
Receivables --
Customer accounts receivable	26	43
Unbilled revenues	36	35
Other accounts and notes receivable	10	11
Affiliated companies	20	51
Income taxes receivable, current	20	0
Fossil fuel stock, at average cost	104	100
Materials and supplies, at average cost	75	62
Prepaid income taxes	39	70
Other regulatory assets, current	95	73
Other current assets	8	5
Total current assets	531	583
Property, Plant, and Equipment:
In service	4,886	4,378
Less accumulated depreciation	1,262	1,173
Plant in service, net of depreciation	3,624	3,205
Construction work in progress	2,254	2,161
Total property, plant, and equipment	5,878	5,366
Other Property and Investments:
Total other property and investments	11	5
Deferred Charges and Other Assets:
Deferred charges related to income taxes	290	226
Other regulatory assets, deferred	525	385
Income taxes receivable, non-current	544	0
Accumulated deferred income taxes	0	33
Other deferred charges and assets	61	44
Total deferred charges and other assets	1,420	688
Total Assets	7,840	6,642
Current Liabilities:
Securities due within one year	728	778
Interest-bearing refundable deposits	0	275
Notes payable	500	0
Accounts payable - Affiliated	85	86
Accounts payable - Other	135	178
Customer deposits	16	15
Accrued taxes --
Accrued income taxes	0	142
Other accrued taxes	85	84
Accrued interest	18	76
Accrued compensation	26	26
Over recovered regulatory clause liabilities	96	1
Mirror CWIP	0	271
Customer liability associated with Kemper refunds	73	0
Other current liabilities	74	46
Total current liabilities	1,836	1,978
Senior notes -
Unamortized Debt Issuance Expense	8	9
Long-term Debt	1,886	1,621
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	762	180
Deferred credits related to income taxes	8	9
Accumulated deferred investment tax credits	5	283
Employee benefit obligations	153	148
Asset retirement obligations	154	48
Unrecognized tax benefits	368	2
Other cost of removal obligations	165	166
Other regulatory liabilities, deferred	71	64
Other deferred credits and liabilities	40	26
Total deferred credits and other liabilities	1,726	926
Total Liabilities	5,448	4,525
Redeemable Preferred Stock	33	33
Common Stockholders' Equity:
Common stock	38	38
Paid-in capital	2,893	2,612
Retained earnings	(566)	(559)
Accumulated other comprehensive loss	(6)	(7)
Common Stockholders' Equity	2,359	2,084
Total stockholders' equity	2,359	2,084
Total Liabilities and Stockholders' Equity	$ 7,840	$ 6,642
Commitments and Contingent Matters
Southern Power [Member]
Current Assets:
Cash and cash equivalents	$ 830	$ 75
Receivables --
Customer accounts receivable	75	77
Other accounts and notes receivable	19	15
Affiliated companies	30	34
Fossil fuel stock, at average cost	16	22
Materials and supplies, at average cost	63	58
Prepaid income taxes	45	19
Prepaid expenses	23	17
Assets from risk management activities	7	5
Total current assets	1,108	322
Property, Plant, and Equipment:
In service	7,275	5,657
Less accumulated depreciation	1,248	1,035
Plant in service, net of depreciation	6,027	4,622
Construction work in progress	1,137	11
Total property, plant, and equipment	7,164	4,633
Other Property and Investments:
Goodwill	2	2
Other intangible assets, net of amortization	317	47
Total other property and investments	319	49
Deferred Charges and Other Assets:
Prepaid long-term service agreements	166	124
Other deferred charges and assets -- affiliated	9	5
Other deferred charges and assets	139	100
Total deferred charges and other assets	314	229
Total Assets	8,905	5,233
Current Liabilities:
Securities due within one year	403	525
Notes payable	137	195
Accounts payable - Affiliated	66	78
Accounts payable - Other	327	30
Accrued taxes --
Accrued income taxes	198	70
Other accrued taxes	5	3
Accrued interest	23	30
Contingent consideration	36	8
Other current liabilities	44	6
Total current liabilities	1,239	945
Senior notes -
Unamortized debt premium (discount), net	0	2
Unamortized Debt Issuance Expense	19	11
Long-term Debt	2,719	1,085
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	601	559
Accumulated deferred investment tax credits	889	601
Accrued income taxes, non-current	109	0
Deferred capacity revenues -- affiliated	17	15
Asset retirement obligations	21	13
Other deferred credits and liabilities	3	5
Total deferred credits and other liabilities	1,640	1,193
Total Liabilities	5,598	3,223
Redeemable Noncontrolling Interest	43	39
Common Stockholders' Equity:
Common stock	0	0
Paid-in capital	1,822	1,176
Retained earnings	657	573
Accumulated other comprehensive loss	4	3
Common Stockholders' Equity	2,483	1,752
Stockholders' Equity Attributable to Noncontrolling Interest	781	219
Total stockholders' equity	3,264	1,971
Total Liabilities and Stockholders' Equity	$ 8,905	$ 5,233
Commitments and Contingent Matters
Southern Power [Member] | 1.85% due 2017 [Member]
Senior notes -
Senior notes	$ 500	$ 0
Southern Power [Member] | 1.50% due 2018 [Member]
Senior notes -
Senior notes	350	0
Southern Power [Member] | 2.375% due 2020 [Member]
Senior notes -
Senior notes	300	0
Southern Power [Member] | 4.15% to 6.375% due Due 2025-2043 [Member]
Senior notes -
Senior notes	1,575	1,075
Southern Power [Member] | 3.50% due 2032-2035 [Member]
Senior notes -
Other long-term notes - variable rate (3.50% at 1/1/16) due 2032-2035	$ 13	$ 19