Georgia Power (GPJA) 10-Q 8 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2016shares
Document Information [Line Items]
Entity Registrant Name	SOUTHERN CO
Entity Central Index Key	92,122
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Amendment Flag	false
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	941,598,673
Alabama Power [Member]
Document Information [Line Items]
Entity Registrant Name	ALABAMA POWER CO
Entity Central Index Key	3,153
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	30,537,500
Georgia Power [Member]
Document Information [Line Items]
Entity Registrant Name	GEORGIA POWER CO
Entity Central Index Key	41,091
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	9,261,500
Gulf Power [Member]
Document Information [Line Items]
Entity Registrant Name	GULF POWER CO
Entity Central Index Key	44,545
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	5,642,717
Mississippi Power [Member]
Document Information [Line Items]
Entity Registrant Name	MISSISSIPPI POWER CO
Entity Central Index Key	66,904
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	1,121,000
Southern Power [Member]
Document Information [Line Items]
Entity Registrant Name	SOUTHERN POWER CO
Entity Central Index Key	1,160,661
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	1,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating Revenues:
Retail revenues	$ 3,748	$ 3,714	$ 7,124	$ 7,256
Wholesale revenues	446	448	842	915
Other electric revenues	166	162	348	325
Other revenues	99	13	137	24
Total operating revenues	4,459	4,337	8,451	8,520
Operating Expenses:
Fuel	1,023	1,200	1,934	2,412
Purchased power	189	171	354	315
Cost of sales	58	0	77	0
Other operations and maintenance	1,099	1,100	2,206	2,222
Depreciation and amortization	569	500	1,110	987
Taxes other than income taxes	255	245	511	497
Estimated loss on Kemper IGCC	81	23	134	32
Total operating expenses	3,274	3,239	6,326	6,465
Operating Income (Loss)	1,185	1,098	2,125	2,055
Other Income and (Expense):
Allowance for equity funds used during construction	45	39	98	102
Interest expense, net of amounts capitalized	(293)	(180)	(539)	(393)
Other income (expense), net	(29)	(12)	(57)	(19)
Total other income and (expense)	(277)	(153)	(498)	(310)
Earnings (Loss) Before Income Taxes	908	945	1,627	1,745
Income taxes (benefit)	272	302	494	576
Net Income (Loss)	636	643	1,133	1,169
Dividends on preferred and preference stock of subsidiaries	12	14	23	31
Less: Net income attributable to noncontrolling interests	12	0	13	0
Net Income (Loss) After Dividends on Preferred and Preference Stock of Subsidiaries	$ 612	$ 629	$ 1,097	$ 1,138
Earnings per share (EPS) -
Basic EPS (in dollars per share)	$ 0.65	$ 0.69	$ 1.19	$ 1.25
Diluted EPS (in dollars per share)	$ 0.65	$ 0.69	$ 1.18	$ 1.25
Average number of shares of common stock outstanding (in millions)
Basic (in shares)	934	909	925	910
Diluted (in shares)	940	912	931	914
Cash dividends paid per share of common stock (in dollars per share)	$ 0.56	$ 0.5425	$ 1.1025	$ 1.0675
Alabama Power [Member]
Operating Revenues:
Retail revenues	$ 1,316	$ 1,326	$ 2,510	$ 2,594
Wholesale revenues, non-affiliates	67	57	130	123
Wholesale revenues, affiliates	9	20	31	35
Other revenues	52	52	105	104
Total operating revenues	1,444	1,455	2,776	2,856
Operating Expenses:
Fuel	295	343	564	653
Purchased power, non-affiliates	40	45	76	86
Purchased power, affiliates	55	49	88	103
Other operations and maintenance	355	370	747	768
Depreciation and amortization	175	160	347	318
Taxes other than income taxes	94	90	191	184
Total operating expenses	1,014	1,057	2,013	2,112
Operating Income (Loss)	430	398	763	744
Other Income and (Expense):
Allowance for equity funds used during construction	6	14	16	29
Interest expense, net of amounts capitalized	(74)	(69)	(147)	(134)
Other income (expense), net	(4)	(14)	(11)	(18)
Total other income and (expense)	(72)	(69)	(142)	(123)
Earnings (Loss) Before Income Taxes	358	329	621	621
Income taxes (benefit)	142	122	245	235
Net Income (Loss)	216	207	376	386
Dividends on preferred and preference stock of subsidiaries	5	7	9	17
Net Income (Loss) After Dividends on Preferred and Preference Stock of Subsidiaries	211	200	367	369
Georgia Power [Member]
Operating Revenues:
Retail revenues	1,907	1,872	3,624	3,686
Wholesale revenues, non-affiliates	40	50	82	118
Wholesale revenues, affiliates	10	4	15	12
Other revenues	94	90	202	178
Total operating revenues	2,051	2,016	3,923	3,994
Operating Expenses:
Fuel	439	503	815	1,029
Purchased power, non-affiliates	92	78	175	138
Purchased power, affiliates	111	115	250	263
Other operations and maintenance	439	467	896	943
Depreciation and amortization	214	202	425	418
Taxes other than income taxes	100	97	197	195
Total operating expenses	1,395	1,462	2,758	2,986
Operating Income (Loss)	656	554	1,165	1,008
Other Income and (Expense):
Allowance for equity funds used during construction			24	10
Interest expense, net of amounts capitalized	(99)	(93)	(193)	(182)
Other income (expense), net	8	1	26	16
Total other income and (expense)	(91)	(92)	(167)	(166)
Earnings (Loss) Before Income Taxes	565	462	998	842
Income taxes (benefit)	213	180	373	320
Net Income (Loss)	352	282	625	522
Dividends on preferred and preference stock of subsidiaries	5	5	9	9
Net Income (Loss) After Dividends on Preferred and Preference Stock of Subsidiaries	347	277	616	513
Gulf Power [Member]
Operating Revenues:
Retail revenues	319	327	602	620
Wholesale revenues, non-affiliates	15	27	31	52
Wholesale revenues, affiliates	15	13	36	35
Other revenues	16	17	31	34
Total operating revenues	365	384	700	741
Operating Expenses:
Fuel	107	122	201	232
Purchased power, non-affiliates	32	25	62	50
Purchased power, affiliates	4	9	5	17
Other operations and maintenance	77	91	155	185
Depreciation and amortization	42	40	80	60
Taxes other than income taxes	29	28	58	56
Total operating expenses	291	315	561	600
Operating Income (Loss)	74	69	139	141
Other Income and (Expense):
Allowance for equity funds used during construction	0	3	0	8
Interest expense, net of amounts capitalized	(12)	(12)	(25)	(26)
Other income (expense), net	(1)	(1)	(2)	(2)
Total other income and (expense)	(13)	(10)	(27)	(20)
Earnings (Loss) Before Income Taxes	61	59	112	121
Income taxes (benefit)	24	21	44	44
Net Income (Loss)	37	38	68	77
Dividends on preferred and preference stock of subsidiaries	3	3	5	5
Net Income (Loss) After Dividends on Preferred and Preference Stock of Subsidiaries	34	35	63	72
Mississippi Power [Member]
Operating Revenues:
Retail revenues	206	189	389	357
Wholesale revenues, non-affiliates	60	63	120	141
Wholesale revenues, affiliates	7	18	16	45
Other revenues	4	5	8	9
Total operating revenues	277	275	533	552
Operating Expenses:
Fuel	81	115	157	229
Purchased power, non-affiliates	1	2	1	3
Purchased power, affiliates	4	2	9	4
Other operations and maintenance	68	68	136	144
Depreciation and amortization	45	30	84	57
Taxes other than income taxes	25	23	50	48
Estimated loss on Kemper IGCC	81	23	134	32
Total operating expenses	305	263	571	517
Operating Income (Loss)	(28)	12	(38)	35
Other Income and (Expense):
Allowance for equity funds used during construction	30	25	59	53
Interest expense, net of amounts capitalized	(15)	30	(31)	19
Other income (expense), net	(1)	(1)	(3)	(2)
Total other income and (expense)	14	54	25	70
Earnings (Loss) Before Income Taxes	(14)	66	(13)	105
Income taxes (benefit)	(17)	16	(27)	20
Net Income (Loss)	3	50	14	85
Dividends on preferred and preference stock of subsidiaries	1	1	1	1
Net Income (Loss) After Dividends on Preferred and Preference Stock of Subsidiaries	2	49	13	84
Southern Power [Member]
Operating Revenues:
Wholesale revenues, non-affiliates	264	250	480	481
Wholesale revenues, affiliates	107	85	204	199
Other revenues	2	2	4	4
Total operating revenues	373	337	688	684
Operating Expenses:
Fuel	96	105	187	243
Purchased power, non-affiliates	21	18	35	34
Purchased power, affiliates	2	4	8	14
Other operations and maintenance	86	69	162	121
Depreciation and amortization	81	60	154	118
Taxes other than income taxes	6	6	13	12
Total operating expenses	292	262	559	542
Operating Income (Loss)	81	75	129	142
Other Income and (Expense):
Interest expense, net of amounts capitalized	(22)	(23)	(43)	(45)
Other income (expense), net	1	1	1	1
Total other income and (expense)	(21)	(22)	(42)	(44)
Earnings (Loss) Before Income Taxes	60	53	87	98
Income taxes (benefit)	(41)	1	(65)	13
Net Income (Loss)	101	52	152	85
Less: Net income attributable to noncontrolling interests	12	6	13	6
Net income attributable to Southern Power Company	$ 89	$ 46	$ 139	$ 79

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Income (loss)	$ 636	$ 643	$ 1,133	$ 1,169
Qualifying hedges:
Changes in fair value, net of tax	(20)	19	(137)	1
Reclassification adjustment for amounts included in net income, net of tax	16	2	18	3
Pension and other post retirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	1	1	2	3
Total other comprehensive income (loss)	(3)	22	(117)	7
Dividends on preferred and preference stock of subsidiaries	12	14	23	31
Comprehensive income attributable to noncontrolling interests	12	0	13	0
Comprehensive Income (Loss)	609	651	980	1,145
Alabama Power [Member]
Net Income (loss)	216	207	376	386
Qualifying hedges:
Changes in fair value, net of tax	0	5	(2)	1
Reclassification adjustment for amounts included in net income, net of tax	1	0	2	1
Pension and other post retirement benefit plans:
Total other comprehensive income (loss)	1	5	0	2
Dividends on preferred and preference stock of subsidiaries	5	7	9	17
Comprehensive Income (Loss)	217	212	376	388
Georgia Power [Member]
Net Income (loss)	352	282	625	522
Qualifying hedges:
Changes in fair value, net of tax	0	14	0	0
Reclassification adjustment for amounts included in net income, net of tax	1	1	1	1
Pension and other post retirement benefit plans:
Total other comprehensive income (loss)	1	15	1	1
Dividends on preferred and preference stock of subsidiaries	5	5	9	9
Comprehensive Income (Loss)	353	297	626	523
Gulf Power [Member]
Net Income (loss)	37	38	68	77
Qualifying hedges:
Changes in fair value, net of tax	(1)	0	(4)	0
Pension and other post retirement benefit plans:
Total other comprehensive income (loss)	(1)	0	(4)	0
Dividends on preferred and preference stock of subsidiaries	3	3	5	5
Comprehensive Income (Loss)	36	38	64	77
Mississippi Power [Member]
Net Income (loss)	3	50	14	85
Pension and other post retirement benefit plans:
Total other comprehensive income (loss)	0	0	0	0
Dividends on preferred and preference stock of subsidiaries	1	1	1	1
Comprehensive Income (Loss)	3	50	14	85
Southern Power [Member]
Net Income (loss)	101	52	152	85
Qualifying hedges:
Changes in fair value, net of tax	(24)	0	(24)	0
Reclassification adjustment for amounts included in net income, net of tax	13	0	14	0
Pension and other post retirement benefit plans:
Total other comprehensive income (loss)	(11)	0	(10)	0
Comprehensive income attributable to noncontrolling interests	12	6	13	6
Comprehensive Income (Loss)	$ 78	$ 46	$ 129	$ 79

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes in fair value, tax	$ (13)	$ 12	$ (85)	$ 1
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	10	1	11	2
Reclassification adjustment for amounts of pension and other post retirement benefit plans included in net income, tax	0	1	1	2
Alabama Power [Member]
Changes in fair value, tax	0	3	(1)	0
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	0	0	1	1
Georgia Power [Member]
Changes in fair value, tax	0	9	0	0
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	0	0	1	1
Gulf Power [Member]
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	(1)	0	(3)	0
Southern Power [Member]
Changes in fair value, tax	(15)	0	(15)	0
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	$ 8	$ 0	$ 8	$ 0

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating Activities:
Net income (loss)	$ 1,133,000,000	$ 1,169,000,000
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	1,306,000,000	1,171,000,000
Deferred income taxes	279,000,000	783,000,000
Allowance for equity funds used during construction	(98,000,000)	(102,000,000)
Stock based compensation expense	69,000,000	66,000,000
Hedge settlements	(201,000,000)	(3,000,000)
Estimated loss on Kemper IGCC	134,000,000	32,000,000
Income taxes receivable, non-current	0	(444,000,000)
Other, net	(69,000,000)	(3,000,000)
Changes in certain current assets and liabilities —
-Receivables	(197,000,000)	(158,000,000)
-Fossil fuel stock	70,000,000	136,000,000
-Other current assets	(53,000,000)	(99,000,000)
-Accounts payable	(71,000,000)	(311,000,000)
-Accrued taxes	74,000,000	(60,000,000)
-Accrued compensation	(222,000,000)	(269,000,000)
-Mirror CWIP	0	82,000,000
-Other current liabilities	(39,000,000)	117,000,000
Net cash provided from (used for) operating activities	2,115,000,000	2,107,000,000
Investing Activities:
Business acquisitions, net of cash acquired	(897,000,000)	(408,000,000)
Property additions	(3,486,000,000)	(2,239,000,000)
Investment in restricted cash	(8,608,000,000)	0
Distributions of restricted cash	649,000,000	0
Nuclear decommissioning trust fund purchases	(585,000,000)	(933,000,000)
Nuclear decommissioning trust fund sales	580,000,000	928,000,000
Cost of removal, net of salvage	(99,000,000)	(87,000,000)
Change in construction payables	(260,000,000)	56,000,000
Prepaid long-term service agreement	(82,000,000)	(110,000,000)
Other investing activities	113,000,000	27,000,000
Net cash used for investing activities	(12,675,000,000)	(2,766,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	471,000,000	184,000,000
Proceeds —
Long-term debt issuances	12,038,000,000	3,075,000,000
Common stock issuances	1,383,000,000	116,000,000
Short-term borrowings	0	320,000,000
Redemptions and repurchases —
Long-term debt	(1,272,000,000)	(939,000,000)
Interest-bearing refundable deposits	0	(275,000,000)
Common stock	0	(115,000,000)
Preferred and preference stock	0	(412,000,000)
Short-term borrowings	(475,000,000)	(250,000,000)
Distributions to noncontrolling interests	(11,000,000)	(1,000,000)
Capital contributions from noncontrolling interests	179,000,000	78,000,000
Purchase of membership interests from noncontrolling interests	(129,000,000)	0
Payment of common stock dividends	(1,023,000,000)	(972,000,000)
Other financing activities	(108,000,000)	(47,000,000)
Net cash provided from (used for) financing activities	11,053,000,000	762,000,000
Net Change in Cash and Cash Equivalents	493,000,000	103,000,000
Cash and Cash Equivalents at Beginning of Period	1,404,000,000	710,000,000
Cash and Cash Equivalents at End of Period	1,897,000,000	813,000,000
Cash paid (received) during the period for --
Interest (net of capitalized amounts)	458,000,000	374,000,000
Income taxes, net	(138,000,000)	(16,000,000)
Noncash Investing and Financing Items [Abstract]
Noncash transactions - Accrued property additions at end of period	549,000,000	345,000,000
Alabama Power [Member]
Operating Activities:
Net income (loss)	376,000,000	386,000,000
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	419,000,000	387,000,000
Deferred income taxes	175,000,000	60,000,000
Allowance for equity funds used during construction	(16,000,000)	(29,000,000)
Other, net	(37,000,000)	(23,000,000)
Changes in certain current assets and liabilities —
-Receivables	64,000,000	(115,000,000)
-Fossil fuel stock	(32,000,000)	19,000,000
-Other current assets	(67,000,000)	(52,000,000)
-Accounts payable	(75,000,000)	(212,000,000)
-Accrued taxes	98,000,000	177,000,000
-Accrued compensation	(50,000,000)	(66,000,000)
-Retail fuel cost over recovery - short-term	(60,000,000)	25,000,000
-Other current liabilities	8,000,000	40,000,000
Net cash provided from (used for) operating activities	803,000,000	597,000,000
Investing Activities:
Property additions	(645,000,000)	(612,000,000)
Nuclear decommissioning trust fund purchases	(200,000,000)	(278,000,000)
Nuclear decommissioning trust fund sales	200,000,000	278,000,000
Cost of removal, net of salvage	(51,000,000)	(28,000,000)
Change in construction payables	(27,000,000)	28,000,000
Other investing activities	(18,000,000)	(14,000,000)
Net cash used for investing activities	(741,000,000)	(626,000,000)
Proceeds —
Senior notes issuances	400,000,000	975,000,000
Capital contributions from parent company	237,000,000	10,000,000
Pollution control revenue bonds	0	80,000,000
Other long-term debt	45,000,000	0
Redemptions and repurchases —
Pollution control revenue bonds	0	(134,000,000)
Senior notes	(200,000,000)	(250,000,000)
Preferred and preference stock	0	(412,000,000)
Payment of common stock dividends	(382,000,000)	(286,000,000)
Other financing activities	(13,000,000)	(32,000,000)
Net cash provided from (used for) financing activities	87,000,000	(49,000,000)
Net Change in Cash and Cash Equivalents	149,000,000	(78,000,000)
Cash and Cash Equivalents at Beginning of Period	194,000,000	273,000,000
Cash and Cash Equivalents at End of Period	343,000,000	195,000,000
Cash paid (received) during the period for --
Interest (net of capitalized amounts)	131,000,000	118,000,000
Income taxes, net	(122,000,000)	47,000,000
Noncash Investing and Financing Items [Abstract]
Noncash transactions - Accrued property additions at end of period	94,000,000	35,000,000
Georgia Power [Member]
Operating Activities:
Net income (loss)	625,000,000	522,000,000
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	530,000,000	512,000,000
Deferred income taxes	157,000,000	(6,000,000)
Allowance for equity funds used during construction	(24,000,000)	(10,000,000)
Deferred expenses	39,000,000	28,000,000
Contract amendment	0	(118,000,000)
Settlement of asset retirement obligations	(52,000,000)	(9,000,000)
Other, net	6,000,000	9,000,000
Changes in certain current assets and liabilities —
-Receivables	(25,000,000)	(21,000,000)
-Fossil fuel stock	61,000,000	101,000,000
-Prepaid income taxes	(1,000,000)	86,000,000
-Other current assets	11,000,000	(38,000,000)
-Accounts payable	6,000,000	(110,000,000)
-Accrued taxes	(137,000,000)	(125,000,000)
-Accrued compensation	(44,000,000)	(61,000,000)
-Other current liabilities	17,000,000	14,000,000
Net cash provided from (used for) operating activities	1,169,000,000	774,000,000
Investing Activities:
Property additions	(1,058,000,000)	(853,000,000)
Nuclear decommissioning trust fund purchases	(386,000,000)	(655,000,000)
Nuclear decommissioning trust fund sales	380,000,000	649,000,000
Cost of removal, net of salvage	(34,000,000)	(46,000,000)
Change in construction payables, net of joint owner portion	(75,000,000)	26,000,000
Prepaid long-term service agreement	(14,000,000)	(40,000,000)
Other investing activities	17,000,000	28,000,000
Net cash used for investing activities	(1,170,000,000)	(891,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	39,000,000	44,000,000
Proceeds —
Senior notes issuances	650,000,000	0
FFB loan	300,000,000	600,000,000
Capital contributions from parent company	239,000,000	23,000,000
Pollution control revenue bonds	0	170,000,000
Short-term borrowings	0	250,000,000
Redemptions and repurchases —
Pollution control revenue bonds	(4,000,000)	(65,000,000)
Senior notes	(500,000,000)	(125,000,000)
Short-term borrowings	0	(250,000,000)
Payment of common stock dividends	(653,000,000)	(517,000,000)
Other financing activities	(16,000,000)	(13,000,000)
Net cash provided from (used for) financing activities	55,000,000	117,000,000
Net Change in Cash and Cash Equivalents	54,000,000	0
Cash and Cash Equivalents at Beginning of Period	67,000,000	24,000,000
Cash and Cash Equivalents at End of Period	121,000,000	24,000,000
Cash paid (received) during the period for --
Interest (net of capitalized amounts)	174,000,000	170,000,000
Income taxes, net	78,000,000	240,000,000
Noncash Investing and Financing Items [Abstract]
Noncash transactions - Accrued property additions at end of period	288,000,000	171,000,000
Gulf Power [Member]
Operating Activities:
Net income (loss)	68,000,000	77,000,000
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	83,000,000	64,000,000
Deferred income taxes	16,000,000	40,000,000
Allowance for equity funds used during construction	0	(8,000,000)
Other, net	(3,000,000)	3,000,000
Changes in certain current assets and liabilities —
-Receivables	(6,000,000)	(15,000,000)
-Fossil fuel stock	34,000,000	6,000,000
-Prepaid income taxes	2,000,000	12,000,000
-Other current assets	(1,000,000)	1,000,000
-Accounts payable	(7,000,000)	(9,000,000)
-Accrued taxes	17,000,000	15,000,000
-Accrued compensation	(12,000,000)	(10,000,000)
-Other current liabilities	4,000,000	(1,000,000)
Net cash provided from (used for) operating activities	195,000,000	183,000,000
Investing Activities:
Property additions	(68,000,000)	(148,000,000)
Cost of removal, net of salvage	(4,000,000)	(7,000,000)
Change in construction payables	(7,000,000)	(15,000,000)
Other investing activities	(5,000,000)	(4,000,000)
Net cash used for investing activities	(84,000,000)	(174,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	46,000,000	4,000,000
Proceeds —
Common stock issuances	0	20,000,000
Short-term borrowings	0	40,000,000
Redemptions and repurchases —
Senior notes	(125,000,000)	0
Payment of common stock dividends	(60,000,000)	(65,000,000)
Other financing activities	0	(3,000,000)
Net cash provided from (used for) financing activities	(139,000,000)	(4,000,000)
Net Change in Cash and Cash Equivalents	(28,000,000)	5,000,000
Cash and Cash Equivalents at Beginning of Period	74,000,000	39,000,000
Cash and Cash Equivalents at End of Period	46,000,000	44,000,000
Cash paid (received) during the period for --
Interest (net of capitalized amounts)	28,000,000	26,000,000
Income taxes, net	(3,000,000)	(9,000,000)
Noncash Investing and Financing Items [Abstract]
Noncash transactions - Accrued property additions at end of period	13,000,000	28,000,000
Mississippi Power [Member]
Operating Activities:
Net income (loss)	14,000,000	85,000,000
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	82,000,000	55,000,000
Deferred income taxes	(16,000,000)	694,000,000
Investment tax credits	0	32,000,000
Allowance for equity funds used during construction	(59,000,000)	(53,000,000)
Regulatory assets associated with Kemper IGCC	(10,000,000)	(50,000,000)
Estimated loss on Kemper IGCC	134,000,000	32,000,000
Income taxes receivable, non-current	0	(544,000,000)
Other, net	3,000,000	8,000,000
Changes in certain current assets and liabilities —
-Receivables	15,000,000	6,000,000
-Fossil fuel stock	6,000,000	5,000,000
-Prepaid income taxes	34,000,000	24,000,000
-Other current assets	(3,000,000)	(7,000,000)
-Accounts payable	(12,000,000)	(25,000,000)
-Accrued taxes	19,000,000	(51,000,000)
-Accrued interest	0	(7,000,000)
-Accrued compensation	(12,000,000)	(12,000,000)
-Over recovered regulatory clause revenues	4,000,000	32,000,000
-Mirror CWIP	0	82,000,000
-Customer liability associated with Kemper refunds	(69,000,000)	0
-Other current liabilities	7,000,000	3,000,000
Net cash provided from (used for) operating activities	137,000,000	309,000,000
Investing Activities:
Property additions	(403,000,000)	(428,000,000)
Change in construction payables	(11,000,000)	(15,000,000)
Capital grant proceeds	137,000,000	0
Other investing activities	(19,000,000)	(17,000,000)
Net cash used for investing activities	(296,000,000)	(460,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	0	475,000,000
Proceeds —
Capital contributions from parent company	226,000,000	77,000,000
Short-term borrowings	0	30,000,000
Long-term debt issuance to parent company	200,000,000	0
Other long-term debt	900,000,000	0
Redemptions and repurchases —
Short-term borrowings	(475,000,000)	0
Long-term debt to parent company	(225,000,000)	0
Other long-term debt	(425,000,000)	(350,000,000)
Other financing activities	(3,000,000)	(2,000,000)
Net cash provided from (used for) financing activities	198,000,000	230,000,000
Net Change in Cash and Cash Equivalents	39,000,000	79,000,000
Cash and Cash Equivalents at Beginning of Period	98,000,000	133,000,000
Cash and Cash Equivalents at End of Period	137,000,000	212,000,000
Cash paid (received) during the period for --
Interest (net of capitalized amounts)	26,000,000	2,000,000
Income taxes, net	(122,000,000)	(181,000,000)
Noncash Investing and Financing Items [Abstract]
Noncash transactions - Accrued property additions at end of period	94,000,000	99,000,000
Issuance of promissory note to parent related to repayment of interest-bearing refundable deposits and accrued interest	0	301,000,000
Southern Power [Member]
Operating Activities:
Net income (loss)	152,000,000	85,000,000
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	159,000,000	121,000,000
Deferred income taxes	(71,000,000)	59,000,000
Investment tax credits	0	153,000,000
Amortization of investment tax credits	(15,000,000)	(10,000,000)
Deferred revenues	(31,000,000)	(21,000,000)
Accrued income taxes, non-current	0	100,000,000
Other, net	9,000,000	10,000,000
Changes in certain current assets and liabilities —
-Receivables	(76,000,000)	(26,000,000)
-Prepaid income taxes	(147,000,000)	(102,000,000)
-Other current assets	5,000,000	5,000,000
-Accounts payable	4,000,000	(31,000,000)
-Accrued taxes	62,000,000	(110,000,000)
-Other current liabilities	0	18,000,000
Net cash provided from (used for) operating activities	51,000,000	251,000,000
Investing Activities:
Business acquisitions, net of cash acquired	(502,000,000)	(408,000,000)
Property additions	(1,281,000,000)	(154,000,000)
Investment in restricted cash	(646,000,000)	0
Distributions of restricted cash	649,000,000	0
Change in construction payables	(137,000,000)	38,000,000
Payments pursuant to long-term service agreements	(43,000,000)	(45,000,000)
Other investing activities	(25,000,000)	(1,000,000)
Net cash used for investing activities	(1,985,000,000)	(570,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	695,000,000	(195,000,000)
Proceeds —
Senior notes issuances	1,241,000,000	650,000,000
Capital contributions from parent company	300,000,000	0
Redemptions and repurchases —
Distributions to noncontrolling interests	(11,000,000)	(1,000,000)
Capital contributions from noncontrolling interests	179,000,000	78,000,000
Purchase of membership interests from noncontrolling interests	(129,000,000)	0
Payment of common stock dividends	(136,000,000)	(65,000,000)
Other financing activities	(13,000,000)	(3,000,000)
Net cash provided from (used for) financing activities	2,126,000,000	464,000,000
Net Change in Cash and Cash Equivalents	192,000,000	145,000,000
Cash and Cash Equivalents at Beginning of Period	830,000,000	75,000,000
Cash and Cash Equivalents at End of Period	1,022,000,000	220,000,000
Cash paid (received) during the period for --
Interest (net of capitalized amounts)	42,000,000	35,000,000
Income taxes, net	115,000,000	(72,000,000)
Noncash Investing and Financing Items [Abstract]
Noncash transactions - Accrued property additions at end of period	$ 108,000,000	$ 38,000,000

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Net cash paid for capitalized interest	$ 61	$ 57
Alabama Power [Member]
Net cash paid for capitalized interest	7	10
Georgia Power [Member]
Net cash paid for capitalized interest	10	5
Gulf Power [Member]
Net cash paid for capitalized interest	0	3
Mississippi Power [Member]
Interest paid	49	39
Net cash paid for capitalized interest	23	37
Southern Power [Member]
Net cash paid for capitalized interest	$ 21	$ 1

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 1,897	$ 1,404
Restricted cash and cash equivalents	7,963	0
Receivables —
Customer accounts receivable	1,281	1,058
Unbilled revenues	590	397
Under recovered regulatory clause revenues	12	63
Income taxes receivable, current	0	144
Other accounts and notes receivable	247	398
Accumulated provision for uncollectible accounts	(14)	(13)
Fossil fuel stock, at average cost	798	868
Materials and supplies, at average cost	1,210	1,061
Vacation pay	181	178
Other regulatory assets, current	350	402
Prepaid expenses	563	495
Other current assets	71	71
Total current assets	15,149	6,526
Property, Plant, and Equipment:
In service	78,112	75,118
Less accumulated provision for depreciation	24,778	24,253
Plant in service, net of depreciation	53,334	50,865
Other utility plant, net	174	233
Nuclear fuel, at amortized cost	934	934
Construction work in progress	9,451	9,082
Total property, plant, and equipment	63,893	61,114
Other Property and Investments:
Goodwill	264	2
Other intangible assets, net of amortization	490	317
Nuclear decommissioning trusts, at fair value	1,578	1,512
Leveraged leases	763	755
Miscellaneous property and investments	230	166
Total other property and investments	3,325	2,752
Deferred Charges and Other Assets:
Deferred charges related to income taxes	1,580	1,560
Unamortized loss on reacquired debt	220	227
Other regulatory assets, deferred	5,460	4,989
Income taxes receivable, non-current	413	413
Other deferred charges and assets	833	737
Total deferred charges and other assets	8,506	7,926
Total Assets	90,873	78,318
Current Liabilities:
Securities due within one year	2,724	2,674
Notes payable	1,372	1,376
Accounts payable —
Accounts payable	1,493	1,905
Customer deposits	408	404
Accrued taxes —
Accrued income taxes	13	19
Other accrued taxes	398	484
Accrued interest	289	249
Accrued vacation pay	229	228
Accrued compensation	335	549
Asset retirement obligations, current	349	217
Liabilities from risk management activities	95	156
Other regulatory liabilities, current	115	278
Other current liabilities	694	590
Total current liabilities	8,514	9,129
Long-term Debt:
Total Long-term Debt	35,368	24,688
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	12,563	12,322
Deferred credits related to income taxes	183	187
Accumulated deferred investment tax credits	1,427	1,219
Employee benefit obligations	2,485	2,582
Asset retirement obligations, deferred	4,129	3,542
Unrecognized tax benefits	380	370
Other cost of removal obligations	1,154	1,162
Other regulatory liabilities, deferred	335	254
Other deferred credits and liabilities	724	720
Total deferred credits and other liabilities	23,380	22,358
Total Liabilities	67,262	56,175
Redeemable Preferred Stock of Subsidiaries	118	118
Redeemable Noncontrolling Interest	47	43
Common Stockholders' Equity:
Common stock	4,708	4,572
Paid-in capital	7,499	6,282
Treasury, at cost	(30)	(142)
Retained earnings (accumulated deficit)	10,085	10,010
Accumulated other comprehensive income (loss)	(247)	(130)
Total common stockholders' equity	22,015	20,592
Preferred and Preference Stock of Subsidiaries	609	609
Noncontrolling Interests	822	781
Total Stockholders' Equity	23,446	21,982
Total Liabilities and Stockholders' Equity	90,873	78,318
Alabama Power [Member]
Current Assets:
Cash and cash equivalents	343	194
Receivables —
Customer accounts receivable	357	332
Unbilled revenues	174	119
Under recovered regulatory clause revenues	7	43
Income taxes receivable, current	0	142
Other accounts and notes receivable	35	20
Affiliated companies	32	50
Accumulated provision for uncollectible accounts	(9)	(10)
Fossil fuel stock, at average cost	271	239
Materials and supplies, at average cost	412	398
Vacation pay	66	66
Other regulatory assets, current	87	115
Prepaid expenses	100	83
Other current assets	10	10
Total current assets	1,885	1,801
Property, Plant, and Equipment:
In service	25,572	24,750
Less accumulated provision for depreciation	8,889	8,736
Plant in service, net of depreciation	16,683	16,014
Nuclear fuel, at amortized cost	368	363
Construction work in progress	423	801
Total property, plant, and equipment	17,474	17,178
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	69	71
Nuclear decommissioning trusts, at fair value	759	737
Miscellaneous property and investments	101	96
Total other property and investments	929	904
Deferred Charges and Other Assets:
Deferred charges related to income taxes	519	522
Deferred under recovered regulatory clause revenues	136	99
Other regulatory assets, deferred	1,100	1,114
Other deferred charges and assets	113	103
Total deferred charges and other assets	1,868	1,838
Total Assets	22,156	21,721
Current Liabilities:
Securities due within one year	200	200
Accounts payable —
Affiliated accounts payable	293	278
Other accounts payable	294	410
Customer deposits	88	88
Accrued taxes —
Accrued income taxes	10	0
Other accrued taxes	93	38
Accrued interest	80	73
Accrued vacation pay	55	55
Accrued compensation	72	119
Liabilities from risk management activities	17	55
Other regulatory liabilities, current	81	240
Other current liabilities	41	39
Total current liabilities	1,324	1,595
Long-term Debt:
Total Long-term Debt	6,894	6,654
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	4,413	4,241
Deferred credits related to income taxes	68	70
Accumulated deferred investment tax credits	114	118
Employee benefit obligations	360	388
Asset retirement obligations, deferred	1,502	1,448
Other cost of removal obligations	699	722
Other regulatory liabilities, deferred	106	136
Deferred over recovered regulatory clause revenues	102	0
Other deferred credits and liabilities	69	76
Total deferred credits and other liabilities	7,433	7,199
Total Liabilities	15,651	15,448
Redeemable Preferred Stock	85	85
Preference Stock	196	196
Common Stockholders' Equity:
Common stock	1,222	1,222
Paid-in capital	2,589	2,341
Retained earnings (accumulated deficit)	2,445	2,461
Accumulated other comprehensive income (loss)	(32)	(32)
Total common stockholders' equity	6,224	5,992
Total Liabilities and Stockholders' Equity	22,156	21,721
Georgia Power [Member]
Current Assets:
Cash and cash equivalents	121	67
Receivables —
Customer accounts receivable	592	541
Unbilled revenues	293	188
Joint owner accounts receivable	51	227
Income taxes receivable, current	0	114
Other accounts and notes receivable	52	57
Affiliated companies	16	18
Accumulated provision for uncollectible accounts	(2)	(2)
Fossil fuel stock, at average cost	340	402
Materials and supplies, at average cost	477	449
Vacation pay	93	91
Other regulatory assets, current	123	123
Prepaid income taxes	157	156
Other current assets	55	92
Total current assets	2,368	2,523
Property, Plant, and Equipment:
In service	33,045	31,841
Less accumulated provision for depreciation	11,087	10,903
Plant in service, net of depreciation	21,958	20,938
Other utility plant, net	174	171
Nuclear fuel, at amortized cost	566	572
Construction work in progress	4,655	4,775
Total property, plant, and equipment	27,353	26,456
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	62	64
Nuclear decommissioning trusts, at fair value	819	775
Miscellaneous property and investments	42	43
Total other property and investments	923	882
Deferred Charges and Other Assets:
Deferred charges related to income taxes	677	679
Other regulatory assets, deferred	2,524	2,152
Other deferred charges and assets	170	173
Total deferred charges and other assets	3,371	3,004
Total Assets	34,015	32,865
Current Liabilities:
Securities due within one year	658	712
Notes payable	197	158
Accounts payable —
Affiliated accounts payable	407	411
Other accounts payable	541	750
Customer deposits	268	264
Accrued taxes —
Accrued income taxes	0	12
Other accrued taxes	199	325
Accrued interest	107	99
Accrued vacation pay	64	62
Accrued compensation	88	142
Asset retirement obligations, current	323	179
Other current liabilities	299	181
Total current liabilities	3,151	3,295
Long-term Debt:
Total Long-term Debt	10,120	9,616
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	5,788	5,627
Deferred credits related to income taxes	104	105
Accumulated deferred investment tax credits	199	204
Employee benefit obligations	901	949
Asset retirement obligations, deferred	2,249	1,737
Other deferred credits and liabilities	302	347
Total deferred credits and other liabilities	9,543	8,969
Total Liabilities	22,814	21,880
Redeemable Preferred Stock	45	45
Preference Stock	221	221
Common Stockholders' Equity:
Common stock	398	398
Paid-in capital	6,527	6,275
Retained earnings (accumulated deficit)	4,024	4,061
Accumulated other comprehensive income (loss)	(14)	(15)
Total common stockholders' equity	10,935	10,719
Total Liabilities and Stockholders' Equity	34,015	32,865
Gulf Power [Member]
Current Assets:
Cash and cash equivalents	46	74
Receivables —
Customer accounts receivable	81	76
Unbilled revenues	77	54
Under recovered regulatory clause revenues	5	20
Income taxes receivable, current	0	27
Other accounts and notes receivable	3	9
Affiliated companies	10	1
Accumulated provision for uncollectible accounts	(1)	(1)
Fossil fuel stock, at average cost	74	108
Materials and supplies, at average cost	56	56
Other regulatory assets, current	65	90
Other current assets	17	22
Total current assets	433	536
Property, Plant, and Equipment:
In service	5,032	5,045
Less accumulated provision for depreciation	1,351	1,296
Plant in service, net of depreciation	3,681	3,749
Other utility plant, net	0	62
Construction work in progress	68	48
Total property, plant, and equipment	3,749	3,859
Other Property and Investments:
Total other property and investments	4	4
Deferred Charges and Other Assets:
Deferred charges related to income taxes	60	61
Other regulatory assets, deferred	523	427
Other deferred charges and assets	49	33
Total deferred charges and other assets	632	521
Total Assets	4,818	4,920
Current Liabilities:
Securities due within one year	195	110
Notes payable	187	142
Accounts payable —
Affiliated accounts payable	46	55
Other accounts payable	44	44
Customer deposits	36	36
Accrued taxes —
Accrued income taxes	5	4
Other accrued taxes	25	9
Accrued interest	8	9
Accrued compensation	13	25
Deferred capacity expense, current	22	22
Liabilities from risk management activities	32	49
Other regulatory liabilities, current	19	22
Other current liabilities	30	40
Total current liabilities	662	567
Long-term Debt:
Total Long-term Debt	987	1,193
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	905	893
Employee benefit obligations	126	129
Deferred capacity expense	130	141
Asset retirement obligations, deferred	128	113
Other cost of removal obligations	237	233
Other regulatory liabilities, deferred	46	47
Other deferred credits and liabilities	90	102
Total deferred credits and other liabilities	1,662	1,658
Total Liabilities	3,311	3,418
Preference Stock	147	147
Common Stockholders' Equity:
Common stock	503	503
Paid-in capital	573	567
Retained earnings (accumulated deficit)	288	285
Accumulated other comprehensive income (loss)	(4)	0
Total common stockholders' equity	1,360	1,355
Total Liabilities and Stockholders' Equity	4,818	4,920
Mississippi Power [Member]
Current Assets:
Cash and cash equivalents	137	98
Receivables —
Customer accounts receivable	35	26
Unbilled revenues	46	36
Income taxes receivable, current	0	20
Other accounts and notes receivable	5	10
Affiliated companies	12	20
Fossil fuel stock, at average cost	99	104
Materials and supplies, at average cost	77	75
Other regulatory assets, current	97	95
Prepaid income taxes	5	39
Other current assets	7	8
Total current assets	520	531
Property, Plant, and Equipment:
In service	4,809	4,886
Less accumulated provision for depreciation	1,248	1,262
Plant in service, net of depreciation	3,561	3,624
Construction work in progress	2,429	2,254
Total property, plant, and equipment	5,990	5,878
Other Property and Investments:
Total other property and investments	11	11
Deferred Charges and Other Assets:
Deferred charges related to income taxes	317	290
Other regulatory assets, deferred	520	525
Income taxes receivable, non-current	544	544
Other deferred charges and assets	85	61
Total deferred charges and other assets	1,466	1,420
Total Assets	7,987	7,840
Current Liabilities:
Securities due within one year	343	728
Notes payable	25	500
Accounts payable —
Affiliated accounts payable	87	85
Other accounts payable	120	135
Customer deposits	16	16
Accrued taxes —
Accrued income taxes	57	0
Other accrued taxes	48	85
Accrued interest	19	18
Accrued compensation	14	26
Asset retirement obligations, current	21	22
Over recovered regulatory clause liabilities	100	96
Customer liability associated with Kemper refunds	5	73
Other current liabilities	41	52
Total current liabilities	896	1,836
Long-term Debt:
Long-term Debt, Affiliated	551	576
Long-term debt, non-affiliated	2,164	1,310
Total Long-term Debt	2,715	1,886
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	773	762
Deferred credits related to income taxes	8	8
Accumulated deferred investment tax credits	5	5
Employee benefit obligations	148	153
Asset retirement obligations, deferred	157	154
Unrecognized tax benefits	368	368
Other cost of removal obligations	169	165
Other regulatory liabilities, deferred	74	71
Other deferred credits and liabilities	40	40
Total deferred credits and other liabilities	1,742	1,726
Total Liabilities	5,353	5,448
Redeemable Preferred Stock	33	33
Common Stockholders' Equity:
Common stock	38	38
Paid-in capital	3,122	2,893
Retained earnings (accumulated deficit)	(553)	(566)
Accumulated other comprehensive income (loss)	(6)	(6)
Total common stockholders' equity	2,601	2,359
Total Liabilities and Stockholders' Equity	7,987	7,840
Southern Power [Member]
Current Assets:
Cash and cash equivalents	1,022	830
Receivables —
Customer accounts receivable	115	75
Other accounts and notes receivable	23	19
Affiliated companies	60	30
Fossil fuel stock, at average cost	14	16
Materials and supplies, at average cost	120	63
Prepaid income taxes	192	45
Other current assets	31	30
Total current assets	1,577	1,108
Property, Plant, and Equipment:
In service	8,348	7,275
Less accumulated provision for depreciation	1,374	1,248
Plant in service, net of depreciation	6,974	6,027
Construction work in progress	1,852	1,137
Total property, plant, and equipment	8,826	7,164
Other Property and Investments:
Goodwill	2	2
Other intangible assets, net of amortization	316	317
Total other property and investments	318	319
Deferred Charges and Other Assets:
Prepaid long-term service agreements	165	166
Other deferred charges and assets -- affiliated	23	9
Other deferred charges and assets	173	139
Total deferred charges and other assets	361	314
Total Assets	11,082	8,905
Current Liabilities:
Securities due within one year	403	403
Notes payable	831	137
Accounts payable —
Affiliated accounts payable	80	66
Other accounts payable	175	327
Accrued taxes —
Accrued income taxes	9	198
Other accrued taxes	16	5
Accrued interest	22	23
Contingent consideration	23	36
Other current liabilities	69	44
Total current liabilities	1,628	1,239
Long-term Debt:
Total Long-term Debt	3,929	2,719
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	524	601
Accumulated deferred investment tax credits	1,107	889
Accrued income taxes, non-current	109	109
Asset retirement obligations, deferred	28	21
Deferred capacity revenues -- affiliated	7	17
Other deferred credits and liabilities	105	3
Total deferred credits and other liabilities	1,880	1,640
Total Liabilities	7,437	5,598
Redeemable Noncontrolling Interest	47	43
Common Stockholders' Equity:
Common stock	0	0
Paid-in capital	2,121	1,822
Retained earnings (accumulated deficit)	661	657
Accumulated other comprehensive income (loss)	(6)	4
Total common stockholders' equity	2,776	2,483
Noncontrolling Interests, Total	822	781
Total Stockholders' Equity	3,598	3,264
Total Liabilities and Stockholders' Equity	$ 11,082	$ 8,905

Condensed Consolidated Balance8

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Other intangible assets, accumulated amortization	$ 14	$ 12
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	942,000,000	915,000,000
Treasury shares at cost	800,000	3,400,000
Alabama Power [Member]
Common stock, par value (in dollars per share)	$ 40	$ 40
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares outstanding	30,537,500	30,537,500
Georgia Power [Member]
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares outstanding	9,261,500	9,261,500
Gulf Power [Member]
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares outstanding	5,642,717	5,642,717
Mississippi Power [Member]
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	1,130,000	1,130,000
Common stock, shares outstanding	1,121,000	1,121,000
Southern Power [Member]
Other intangible assets, accumulated amortization	$ 14	$ 12
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000	1,000,000
Common stock, shares outstanding	1,000	1,000

Introduction

Introduction	6 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
INTRODUCTION	INTRODUCTION The condensed quarterly financial statements of each registrant included herein have been prepared by such registrant, without audit, pursuant to the rules and regulations of the SEC. The Condensed Balance Sheets as of December 31, 2015 have been derived from the audited financial statements of each registrant. In the opinion of each registrant's management, the information regarding such registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended June 30, 2016 and 2015 . Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations, although each registrant believes that the disclosures regarding such registrant are adequate to make the information presented not misleading. Disclosures which would substantially duplicate the disclosures in the Form 10-K and details which have not changed significantly in amount or composition since the filing of the Form 10-K are generally omitted from this Quarterly Report on Form 10-Q unless specifically required by GAAP. Therefore, these Condensed Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K. Due to the seasonal variations in the demand for energy, operating results for the periods presented are not necessarily indicative of the operating results to be expected for the full year. Certain prior year data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the results of operations, financial position, or cash flows of any registrant. Recently Issued Accounting Standards On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize on the balance sheet a lease liability and a right-of-use asset for all leases. ASU 2016-02 also changes the recognition, measurement, and presentation of expense associated with leases and provides clarification regarding the identification of certain components of contracts that would represent a lease. The accounting required by lessors is relatively unchanged and there is no change to the accounting for existing leveraged leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The registrants are currently evaluating the new standard and have not yet determined its ultimate impact; however, adoption of ASU 2016-02 is expected to have a significant impact on Southern Company and the traditional electric operating companies' balance sheets. On March 30, 2016, the FASB issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09). ASU 2016-09 changes the accounting for income taxes and the cash flow presentation for share-based payment award transactions. Most significantly, entities are required to recognize all excess tax benefits and deficiencies related to the exercise or vesting of stock compensation as income tax expense or benefit in the income statement. Southern Company and the traditional electric operating companies currently recognize any excess tax benefits and deficiencies related to the exercise and vesting of stock compensation in additional paid-in capital. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016. Early adoption is permitted and Southern Company and the traditional electric operating companies intend to adopt the ASU in the fourth quarter 2016. The adoption is not expected to have a material impact on the results of operations, financial position, or cash flows of Southern Company and the traditional electric operating companies. Affiliate Transactions In 2014, prior to Southern Company's acquisition of PowerSecure International, Inc. (PowerSecure) on May 9, 2016, Georgia Power entered into two agreements with PowerSecure to build solar power generation facilities at two U.S. Army bases, as approved by the Georgia PSC. Payments of approximately $102 million made by Georgia Power to PowerSecure under the two agreements since inception in 2014 are included in CWIP at June 30, 2016 . PowerSecure construction service costs of approximately $13 million are included in accounts payable, affiliated in Georgia Power's balance sheet at June 30, 2016 . The facilities will be owned and operated by Georgia Power and are expected to be operational by the end of 2016. The ultimate outcome of this matter cannot be determined at this time. See Note (I) under " Southern Company – Acquisition of PowerSecure International, Inc. " for additional information regarding Southern Company's acquisition of PowerSecure. Asset Retirement Obligations See Note 1 to the financial statements of Southern Company, Alabama Power, Georgia Power, Gulf Power, and Mississippi Power under "Asset Retirement Obligations and Other Costs of Removal" in Item 8 of the Form 10-K for additional information regarding the EPA's regulation of CCR. The cost estimates below are based on information as of June 30, 2016 using various assumptions related to closure and post-closure costs, timing of future cash outlays, inflation and discount rates, and the potential methods for complying with the Disposal of Coal Combustion Residuals from Electric Utilities final rule requirements for closure in place or by other methods. As further analysis is performed, including evaluation of the expected method of compliance, refinement of assumptions underlying the cost estimates, such as the quantities of CCR at each site, and the determination of timing, including the potential for closing ash ponds prior to the end of their currently anticipated useful life, the traditional electric operating companies expect to continue to periodically update these estimates. As of June 30, 2016 , details of the asset retirement obligations (ARO) included in the registrants' Condensed Balance Sheets were as follows: Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Balance at beginning of year $ 3,759 $ 1,448 $ 1,916 $ 130 $ 177 $ 21 Liabilities incurred 9 5 — — — 4 Liabilities settled (66 ) (6 ) (52 ) (1 ) (7 ) — Accretion 77 36 34 1 2 1 Cash flow revisions 699 19 673 3 6 2 Balance at end of period $ 4,478 $ 1,502 $ 2,571 $ 133 $ 178 $ 28 The traditional electric operating companies' increases in cash flow revisions for the six months ended June 30, 2016 primarily relate to changes in ash pond closure strategy. The increase for Georgia Power was due to its decision in June 2016 to cease operating and stop receiving coal ash at all of its ash ponds within the next three years and to eventually close all of its ash ponds either by removal, consolidation, and/or recycling for the beneficial use of coal ash or through closure in place using advanced engineering methods. Goodwill and Other Intangible Assets Goodwill and other intangible assets consisted of the following: At June 30, 2016 Estimated Useful Life Gross Carrying Amount Accumulated Amortization Intangible Assets, Net (in millions) Intangibles subject to amortization: Southern Company Customer relationships 14-26 years $ 47 $ — $ 47 Trade names 5-9 years 43 — 43 Patents 3-10 years 4 — 4 Backlog 5 years 5 — 5 Southern Power PPA fair value adjustments 20 years 330 (14 ) 316 Total intangibles subject to amortization $ 429 $ (14 ) $ 415 Intangibles not subject to amortization: Southern Company Federal Communications Commission licenses $ 75 $ — $ 75 Goodwill: Southern Company $ 262 $ — $ 262 Southern Power 2 — 2 Total goodwill and other intangible assets $ 768 $ (14 ) $ 754 Amortization expense associated with intangible assets during the three and six months ended June 30, 2016 was immaterial. Intangibles at December 31, 2015 consisted primarily of Southern Power's PPA fair value adjustments with a net carrying amount of $317 million . The increases in goodwill and other intangibles relate to Southern Company's acquisition of PowerSecure on May 9, 2016. See Note 12 to the financial statements of Southern Company under "Southern Power" and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information regarding Southern Power's PPA fair value adjustments. See Note (I) under " Southern Company – Acquisition of PowerSecure International, Inc. " for additional information regarding Southern Company's acquisition of PowerSecure.

Contingencies and Regulatory Ma

Contingencies and Regulatory Matters	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES AND REGULATORY MATTERS	CONTINGENCIES AND REGULATORY MATTERS See Note 3 to the financial statements of the registrants in Item 8 of the Form 10-K for information relating to various lawsuits, other contingencies, and regulatory matters. General Litigation Matters Each registrant is subject to certain claims and legal actions arising in the ordinary course of business. In addition, business activities of Southern Company's subsidiaries are subject to extensive governmental regulation related to public health and the environment, such as regulation of air emissions and water discharges. Litigation over environmental issues and claims of various types, including property damage, personal injury, common law nuisance, and citizen enforcement of environmental requirements such as air quality and water standards, has occurred throughout the U.S. This litigation has included claims for damages alleged to have been caused by CO 2 and other emissions, CCR, and alleged exposure to hazardous materials, and/or requests for injunctive relief in connection with such matters. The ultimate outcome of such pending or potential litigation against each registrant and any subsidiaries cannot be predicted at this time; however, for current proceedings not specifically reported herein or in Note 3 to the financial statements of each registrant in Item 8 of the Form 10-K, management does not anticipate that the ultimate liabilities, if any, arising from such current proceedings would have a material effect on such registrant's financial statements. Environmental Remediation The Southern Company system must comply with environmental laws and regulations that cover the handling and disposal of waste and releases of hazardous substances. Under these various laws and regulations, the Southern Company system could incur substantial costs to clean up affected sites. The traditional electric operating companies have each received authority from their respective state PSCs to recover approved environmental compliance costs through regulatory mechanisms. These rates are adjusted annually or as necessary within limits approved by the state PSCs. Georgia Power's environmental remediation liability as of June 30, 2016 was $23 million . Georgia Power has been designated or identified as a potentially responsible party (PRP) at sites governed by the Georgia Hazardous Site Response Act and/or by the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), including a site in Brunswick, Georgia on the CERCLA National Priorities List. The PRPs at the Brunswick site have completed a removal action as ordered by the EPA. On July 29, 2016, Honeywell International, Inc. and Georgia Power entered into a consent decree with the EPA to perform additional remediation at the site. Additional response actions at the site are anticipated. In September 2015, Georgia Power entered into an allocation agreement with another PRP, under which that PRP will be responsible (as between Georgia Power and that PRP) for paying and performing certain investigation, assessment, remediation, and other incidental activities at the Brunswick site, including costs associated with implementation of the consent decree. Assessment and potential cleanup of other sites are anticipated. The ultimate outcome of these matters will depend upon the success of defenses asserted, the ultimate number of PRPs participating in the cleanup, and numerous other factors and cannot be determined at this time; however, as a result of Georgia Power's regulatory treatment for environmental remediation expenses, these matters are not expected to have a material impact on Southern Company's or Georgia Power's financial statements. Gulf Power's environmental remediation liability includes estimated costs of environmental remediation projects of approximately $46 million as of June 30, 2016 . These estimated costs primarily relate to site closure criteria by the Florida Department of Environmental Protection (FDEP) for potential impacts to soil and groundwater from herbicide applications at Gulf Power substations. The schedule for completion of the remediation projects is subject to FDEP approval. The projects have been approved by the Florida PSC for recovery through Gulf Power's environmental cost recovery clause; therefore, these liabilities have no impact on net income. The final outcome of these matters cannot be determined at this time. However, based on the currently known conditions at these sites and the nature and extent of activities relating to these sites, management of Southern Company and Gulf Power does not believe that additional liabilities, if any, at these sites would be material to their respective financial statements . FERC Matters Municipal and Rural Associations Tariff See Note 3 to the financial statements of Mississippi Power under "FERC Matters" in Item 8 of the Form 10-K for additional information regarding a settlement agreement entered into by Mississippi Power regarding the establishment of a regulatory asset for Kemper IGCC-related costs. See " Integrated Coal Gasification Combined Cycle " herein for information regarding Mississippi Power's construction of the Kemper IGCC. On March 31, 2016, Mississippi Power reached a settlement agreement with its wholesale customers and filed a request with the FERC for an increase in wholesale base revenues under the Municipal and Rural Associations (MRA) cost-based electric tariff. The settlement agreement, accepted by the FERC, effective for services rendered beginning May 1, 2016, provides that base rates under the MRA cost-based electric tariff will produce additional annual base revenues of $7 million . The increase is primarily due to the Plant Daniel Units 1 and 2 scrubbers, which were placed in service in November 2015. Additionally, under the settlement agreement, the tariff customers agreed to similar regulatory treatment for MRA tariff ratemaking as the treatment approved for retail ratemaking under the December 2015 Mississippi PSC order authorizing rates providing recovery of assets previously placed in service (In-Service Asset Rate Order). This regulatory treatment primarily includes (i) recovery of the Kemper IGCC assets currently operational and providing service to customers and other related costs, (ii) amortization of the Kemper IGCC-related regulatory assets included in rates under the settlement agreement over 36 months, (iii) Kemper IGCC-related expenses included in rates under the settlement agreement no longer being deferred and charged to expense, and (iv) removing all of the Kemper IGCC CWIP from rate base with a corresponding increase in accrual of AFUDC. The additional resulting AFUDC is estimated to be approximately $8 million through the Kemper IGCC's projected in-service date of October 31, 2016. Fuel Cost Recovery Mississippi Power has a wholesale MRA and a Market Based (MB) fuel cost recovery factor. At June 30, 2016 , the amount of over-recovered wholesale MRA fuel costs included in the balance sheets was $23 million compared to $24 million at December 31, 2015 . See Note 3 to the financial statements of Mississippi Power under "FERC Matters – Fuel Cost Recovery" in Item 8 of the Form 10-K for additional information. Market-Based Rate Authority The traditional electric operating companies and Southern Power have authority from the FERC to sell electricity at market-based rates. Since 2008, that authority, for certain balancing authority areas, has been conditioned on compliance with the requirements of an energy auction, which the FERC found to be tailored mitigation that addresses potential market power concerns. In accordance with FERC regulations governing such authority, the traditional electric operating companies and Southern Power filed a triennial market power analysis in 2014, which included continued reliance on the energy auction as tailored mitigation. In April 2015, the FERC issued an order finding that the traditional electric operating companies' and Southern Power's existing tailored mitigation may not effectively mitigate the potential to exert market power in certain areas served by the traditional electric operating companies and in some adjacent areas. The FERC directed the traditional electric operating companies and Southern Power to show why market-based rate authority should not be revoked in these areas or to provide a mitigation plan to further address market power concerns. The traditional electric operating companies and Southern Power filed a request for rehearing in May 2015 and in June 2015 filed their response with the FERC. The ultimate outcome of this matter cannot be determined at this time. Retail Regulatory Matters Alabama Power See Note 3 to the financial statements of Southern Company and Alabama Power under "Retail Regulatory Matters – Alabama Power" and "Retail Regulatory Matters," respectively, in Item 8 of the Form 10-K for additional information regarding Alabama Power's recovery of retail costs through various regulatory clauses and accounting orders. The balance of each regulatory clause recovery on the balance sheet follows: Regulatory Clause Balance Sheet Line Item June 30, December 31, 2015 (in millions) Rate CNP Compliance Under recovered regulatory clause revenues $ 7 $ 43 Deferred under recovered regulatory clause revenues 21 — Rate CNP PPA Deferred under recovered regulatory clause revenues 115 99 Retail Energy Cost Recovery Other regulatory liabilities, current 75 238 Deferred over recovered regulatory clause revenues 102 — Natural Disaster Reserve Other regulatory liabilities, deferred 72 75 Environmental Accounting Order In April 2016, as part of its environmental compliance strategy, Alabama Power ceased using coal at Plant Greene County Units 1 and 2 ( 300 MWs representing Alabama Power's ownership interest) and began operating Units 1 and 2 solely on natural gas in May 2016 and July 2016, respectively. Georgia Power Rate Plans See Note 3 to the financial statements of Southern Company and Georgia Power under "Retail Regulatory Matters – Georgia Power – Rate Plans" and "Retail Regulatory Matters – Rate Plans," respectively, in Item 8 of the Form 10-K for additional information. Georgia Power's revenues from regulated retail operations are collected through various rate mechanisms subject to the oversight of the Georgia PSC. Georgia Power currently recovers its costs from the regulated retail business through the 2013 ARP, which includes traditional base tariff rates, Demand-Side Management tariffs, Environmental Compliance Cost Recovery tariffs, and Municipal Franchise Fee tariffs. In addition, financing costs related to the construction of Plant Vogtle Units 3 and 4 are being collected through the NCCR tariff and fuel costs are collected through separate fuel cost recovery tariffs. See " Fuel Cost Recovery " herein and Note 3 to the financial statements of Georgia Power under "Retail Regulatory Matters – Nuclear Construction" and Southern Company under "Retail Regulatory Matters – Georgia Power – Fuel Cost Recovery" and " – Nuclear Construction" in Item 8 of the Form 10-K for additional information regarding fuel cost recovery and the NCCR tariff, respectively. Pursuant to the terms and conditions of a settlement agreement related to Southern Company's acquisition of Southern Company Gas approved by the Georgia PSC on April 14, 2016, Georgia Power's 2013 ARP will continue in effect until December 31, 2019, and Georgia Power will be required to file its next base rate case by July 1, 2019. Furthermore, through December 31, 2019, Georgia Power and Atlanta Gas Light Company (collectively, Utilities) each will retain their respective merger savings, net of transition costs, as defined in the settlement agreement; through December 31, 2022, such net merger savings applicable to each utility will be shared on a 60 / 40 basis between their respective customers and the Utilities; thereafter, all merger savings will be retained by customers. See Note (I) under " Southern Company – Merger with Southern Company Gas " for additional information regarding the Merger. Integrated Resource Plan See Note 3 to the financial statements of Southern Company and Georgia Power under "Retail Regulatory Matters – Georgia Power – Integrated Resource Plan" and "Retail Regulatory Matters – Integrated Resource Plan," respectively, in Item 8 of the Form 10-K for additional information regarding Georgia Power's triennial Integrated Resource Plan (2016 IRP). On July 28, 2016, the Georgia PSC voted to approve the 2016 IRP including the decertification and retirement of Plant Mitchell Units 3, 4A, and 4B ( 217 MWs) and Plant Kraft Unit 1 combustion turbine ( 17 MWs), as well as the decertification of the Intercession City unit ( 143 MWs total capacity). On August 2, 2016, the Plant Mitchell and Plant Kraft units were retired. Georgia Power exercised its contractual option to sell its 33% ownership interest in the Intercession City unit to Duke Energy Florida, Inc., with an expected closing date in late August 2016. Additionally, the Georgia PSC approved Georgia Power's environmental compliance strategy and related expenditures proposed in the 2016 IRP, including measures taken to comply with existing government-imposed environmental mandates, subject to limits on expenditures for Plant McIntosh Unit 1 and Plant Hammond Units 1 through 4. The Georgia PSC approved reclassification of the remaining net book value of Plant Mitchell Unit 3 and costs associated with materials and supplies remaining at the unit retirement date to a regulatory asset. Recovery of the unit's net book value will continue through December 31, 2019, as provided in the 2013 ARP. Recovery of the remaining balance of the unit's net book value as of December 31, 2019 and costs associated with materials and supplies remaining at the unit retirement date will be deferred for consideration in Georgia Power's 2019 general base rate case. The Georgia PSC also approved the Renewable Energy Development Initiative to procure an additional 1,200 MWs of renewable resources primarily utilizing market-based prices established through a competitive bidding process with expected in-service dates between 2018 and 2021. Additionally, 200 MWs of self-build capacity for use by Georgia Power was approved, as well as consideration for no more than 200 MWs of capacity as part of a renewable commercial and industrial program. The Georgia PSC also approved recovery of costs up to $99 million through June 30, 2019 to preserve the nuclear option at a future generation site in Stewart County, Georgia. The timing of cost recovery will be determined by the Georgia PSC in a future base rate case. The ultimate outcome of this matter cannot be determined at this time. Fuel Cost Recovery See Note 3 to the financial statements of Southern Company and Georgia Power under "Retail Regulatory Matters – Georgia Power – Fuel Cost Recovery" and "Retail Regulatory Matters – Fuel Cost Recovery," respectively, in Item 8 of the Form 10-K for additional information. As of June 30, 2016 and December 31, 2015 , Georgia Power's over recovered fuel balance totaled $164 million and $116 million , respectively, and is included in current liabilities and other deferred liabilities on Southern Company's and Georgia Power's Condensed Balance Sheets. On May 17, 2016, the Georgia PSC approved Georgia Power's request to decrease fuel rates by 15% effective June 1, 2016, which will reduce annual billings by approximately $313 million . Georgia Power is currently scheduled to file its next fuel case by February 28, 2017. Fuel cost recovery revenues are adjusted for differences in actual recoverable fuel costs and amounts billed in current regulated rates. Accordingly, changes in the billing factor will not have a significant effect on Southern Company's or Georgia Power's revenues or net income, but will affect cash flow. Nuclear Construction See Note 3 to the financial statements of Southern Company and Georgia Power under "Retail Regulatory Matters – Georgia Power – Nuclear Construction" and "Retail Regulatory Matters – Nuclear Construction," respectively, in Item 8 of the Form 10-K for additional information regarding Georgia Power's construction of Plant Vogtle Units 3 and 4, Vogtle Construction Monitoring (VCM) reports, the NCCR tariff, the Vogtle Construction Litigation (as defined below), and the Contractor Settlement Agreement (as defined below). In 2008, Georgia Power, acting for itself and as agent for the Vogtle Owners, entered into an agreement with the Contractor, pursuant to which the Contractor agreed to design, engineer, procure, construct, and test Plant Vogtle Units 3 and 4 (Vogtle 3 and 4 Agreement). Under the terms of the Vogtle 3 and 4 Agreement, the Vogtle Owners agreed to pay a purchase price subject to certain price escalations and adjustments, including fixed escalation amounts and index-based adjustments, as well as adjustments for change orders, and performance bonuses for early completion and unit performance. The Vogtle 3 and 4 Agreement also provides for liquidated damages upon the Contractor's failure to fulfill the schedule and performance guarantees, subject to a cap. In addition, the Vogtle 3 and 4 Agreement provides for limited cost sharing by the Vogtle Owners for Contractor costs under certain conditions (which have not occurred), with maximum additional capital costs under this provision attributable to Georgia Power (based on Georgia Power's ownership interest) of approximately $114 million . Each Vogtle Owner is severally (and not jointly) liable for its proportionate share, based on its ownership interest, of all amounts owed to the Contractor under the Vogtle 3 and 4 Agreement. Georgia Power's proportionate share is 45.7% . On December 31, 2015, Westinghouse acquired Stone & Webster, Inc. from Chicago Bridge & Iron Company, N.V. (CB&I) and changed the name of Stone & Webster, Inc. to WECTEC Global Project Services Inc. (WECTEC). Certain obligations of Westinghouse and WECTEC under the Vogtle 3 and 4 Agreement were originally guaranteed by Toshiba Corporation (Westinghouse's parent company) and The Shaw Group Inc. (which is now a subsidiary of CB&I), respectively. On March 9, 2016, in connection with Westinghouse's acquisition of WECTEC and pursuant to the settlement agreement described below, the guarantee of The Shaw Group Inc. was terminated. The guarantee of Toshiba Corporation remains in place. In the event of certain credit rating downgrades of any Vogtle Owner, such Vogtle Owner will be required to provide a letter of credit or other credit enhancement. Additionally, as a result of credit rating downgrades of Toshiba Corporation, Westinghouse provided the Vogtle Owners with letters of credit in an aggregate amount of $920 million in accordance with, and subject to adjustment under, the terms of the Vogtle 3 and 4 Agreement. The Vogtle Owners may terminate the Vogtle 3 and 4 Agreement at any time for their convenience, provided that the Vogtle Owners will be required to pay certain termination costs. The Contractor may terminate the Vogtle 3 and 4 Agreement under certain circumstances, including certain Vogtle Owner suspension or delays of work, action by a governmental authority to permanently stop work, certain breaches of the Vogtle 3 and 4 Agreement by the Vogtle Owners, Vogtle Owner insolvency, and certain other events. In 2009, the Georgia PSC voted to certify construction of Plant Vogtle Units 3 and 4. Georgia Power is required to file semi-annual VCM reports with the Georgia PSC by February 28 and August 31 each year. If the projected construction capital costs to be borne by Georgia Power increase by 5% above the certified cost or the projected in-service dates are significantly extended, Georgia Power is required to seek an amendment to the Plant Vogtle Units 3 and 4 certificate from the Georgia PSC. In February 2013, Georgia Power requested an amendment to the certificate to increase the estimated in-service capital cost of Plant Vogtle Units 3 and 4 from $4.4 billion to $4.8 billion and to extend the estimated in-service dates to the fourth quarter 2017 (from April 2016) and the fourth quarter 2018 (from April 2017) for Plant Vogtle Units 3 and 4, respectively. In October 2013, the Georgia PSC approved a stipulation (2013 Stipulation) between Georgia Power and the Georgia PSC Staff (Staff) to waive the requirement to amend the Plant Vogtle Units 3 and 4 certificate until the completion of Plant Vogtle Unit 3 or earlier if deemed appropriate by the Georgia PSC and Georgia Power. On April 15, 2015, the Georgia PSC issued a procedural order in connection with the twelfth VCM report, which included a requested amendment (Requested Amendment) to the Plant Vogtle Units 3 and 4 certificate to reflect the Contractor's revised forecast for completion of Plant Vogtle Units 3 and 4 (second quarter of 2019 and second quarter of 2020, respectively) as well as additional estimated Vogtle Owner's costs, of approximately $10 million per month, including property taxes, oversight costs, compliance costs, and other operational readiness costs to include the estimated Vogtle Owner's costs associated with the proposed 18 -month Contractor delay and to increase the estimated total in-service capital cost of Plant Vogtle Units 3 and 4 to $5.0 billion . Pursuant to the Georgia PSC's procedural order, the Georgia PSC deemed the Requested Amendment unnecessary and withdrawn until the completion of construction of Plant Vogtle Unit 3 consistent with the 2013 Stipulation. The Georgia PSC recognized that the certified cost and the 2013 Stipulation do not constitute a cost recovery cap. In accordance with the Georgia Integrated Resource Planning Act, any costs incurred by Georgia Power in excess of the certified amount will be included in rate base, provided Georgia Power shows the costs to be reasonable and prudent. Financing costs up to the certified amount will be collected through the NCCR tariff until the units are placed in service and contemplated in a general base rate case, while financing costs on any construction-related costs in excess of the $4.4 billion certified amount are expected to be recovered through AFUDC. On December 31, 2015, Westinghouse and the Vogtle Owners entered into a definitive settlement agreement (Contractor Settlement Agreement) to resolve disputes between the Vogtle Owners and the Contractor under the Vogtle 3 and 4 Agreement, including litigation that was pending in the U.S. District Court for the Southern District of Georgia (Vogtle Construction Litigation). Effective December 31, 2015, Georgia Power, acting for itself and as agent for the other Vogtle Owners, and the Contractor entered into an amendment to the Vogtle 3 and 4 Agreement to implement the Contractor Settlement Agreement. The Contractor Settlement Agreement and the related amendment to the Vogtle 3 and 4 Agreement (i) restrict the Contractor's ability to seek further increases in the contract price by clarifying and limiting the circumstances that constitute nuclear regulatory changes in law; (ii) provide for enhanced dispute resolution procedures; (iii) revise the guaranteed substantial completion dates to match the current estimated in-service dates of June 30, 2019 for Unit 3 and June 30, 2020 for Unit 4; (iv) provide that delay liquidated damages will commence from the current estimated nuclear fuel loading date for each unit, which is December 31, 2018 for Unit 3 and December 31, 2019 for Unit 4; and (v) provide that Georgia Power, based on its ownership interest, will pay to the Contractor and capitalize to the project cost approximately $350 million , of which approximately $250 million had been paid as of June 30, 2016 . In addition, the Contractor Settlement Agreement provides for the resolution of other open existing items relating to the scope of the project under the Vogtle 3 and 4 Agreement, including cyber security, for which costs were reflected in Georgia Power's previously disclosed in-service cost estimate. Further, as part of the settlement and Westinghouse's acquisition of WECTEC: (i) Westinghouse engaged Fluor Enterprises, Inc., a subsidiary of Fluor Corporation, as a new construction subcontractor; and (ii) the Vogtle Owners, CB&I, and The Shaw Group Inc. entered into mutual releases of any and all claims arising out of events or circumstances in connection with the construction of Plant Vogtle Units 3 and 4 that occurred on or before the date of the Contractor Settlement Agreement. On January 5, 2016, the Vogtle Construction Litigation was dismissed with prejudice. On January 21, 2016, Georgia Power submitted the Contractor Settlement Agreement and the related amendment to the Vogtle 3 and 4 Agreement to the Georgia PSC for its review. In accordance with the Georgia PSC's subsequent order, on April 5, 2016, Georgia Power filed supplemental information in support of the Contractor Settlement Agreement and Georgia Power's position that all construction costs to date have been prudently incurred and that the current estimated in-service capital cost and schedule are reasonable. The Staff is conducting a review of all costs incurred related to Plant Vogtle Units 3 and 4, the schedule for completion of Plant Vogtle Units 3 and 4, and the Contractor Settlement Agreement, and is authorized to engage in related settlement discussions with Georgia Power and any intervenors. The order provides that the Staff is required to report to the Georgia PSC by October 19, 2016 with respect to the status of its review and any settlement-related negotiations. If a settlement with the Staff is reached with respect to costs of Plant Vogtle Units 3 and 4, the Georgia PSC will then conduct a hearing to consider whether to approve that settlement. If a settlement with the Staff is not reached, the Georgia PSC will determine how to proceed, including (i) modifying the 2013 Stipulation, (ii) directing Georgia Power to file a request for an amendment to the certificate for Plant Vogtle Units 3 and 4, (iii) issuing a scheduling order to address remaining disputed issues, or (iv) taking any other option within its authority. The Georgia PSC has approved thirteen VCM reports covering the periods through June 30, 2015, including construction capital costs incurred, which through that date totaled $3.1 billion . On February 26, 2016, Georgia Power filed its fourteenth VCM report with the Georgia PSC covering the period from July 1 through December 31, 2015. The fourteenth VCM report does not include a requested amendment to the certified cost of Plant Vogtle Units 3 and 4. Georgia Power is requesting approval of $160 million of construction capital costs incurred during that period. Georgia Power incurred approximately $141 million in total construction capital costs during the period of January 1, 2016 through June 30, 2016. Georgia Power's CWIP balance for Plant Vogtle Units 3 and 4 was $3.7 billion as of June 30, 2016 . The in-service capital cost forecast is $5.44 billion and includes costs related to the Contractor Settlement Agreement. Estimated financing costs during the construction period total approximately $2.4 billion , of which $1.1 billion had been incurred through June 30, 2016 . There have been technical and procedural challenges to the construction and licensing of Plant Vogtle Units 3 and 4, at the federal and state level, and additional challenges may arise as construction proceeds. Processes are in place that are designed to assure compliance with the requirements specified in the Westinghouse Design Control Document and the combined construction and operating licenses, including inspections by Southern Nuclear and the NRC that occur throughout construction. As a result of such compliance processes, certain license amendment requests have been filed and approved or are pending before the NRC. Various design and other licensing-based compliance matters, including the timely resolution of Inspections, Tests, Analyses, and Acceptance Criteria and the related approvals by the NRC, may arise as construction proceeds, which may result in additional license amendments or require other resolution. If any license amendment requests or other licensing-based compliance issues are not resolved in a timely manner, there may be delays in the project schedule that could result in increased costs either to the Vogtle Owners or the Contractor or to both. As construction continues, the risk remains that challenges with Contractor performance including labor productivity, fabrication, assembly, delivery, and installation of plant equipment, the shield building and structural modules, delays in the receipt of the remaining permits necessary for the operation of Plant Vogtle Units 3 and 4, or other issues could arise and may further impact project schedule and cost. In addition, the IRS allocated production tax credits to each of Plant Vogtle Units 3 and 4, which require the applicable unit to be placed in service before 2021. Future claims by the Contractor or Georgia Power (on behalf of the Vogtle Owners) could arise throughout construction. These claims may be resolved through formal and informal dispute resolution procedures under the Vogtle 3 and 4 Agreement and, under the enhanced dispute resolution procedures, may be resolved through litigation after the completion of nuclear fuel load for both units. The ultimate outcome of these matters cannot be determined at this time. Gulf Power Retail Base Rate Case See Note 3 to the financial statements of Gulf Power under "Retail Regulatory Matters – Retail Base Rate Case" in Item 8 of the Form 10-K for additional information. In 2013, the Florida PSC approved a settlement agreement that authorized Gulf Power to reduce depreciation and record a regulatory asset up to $62.5 million from January 2014 through June 2017. In any given month, such depreciation reduction may not exceed the amount necessary for the retail ROE, as reported to the Florida PSC monthly, to reach the midpoint of the authorized retail ROE range then in effect. For 2014, 2015 , and the first six months of 2016 , Gulf Power recognized reductions in depreciation of $8.4 million , $20.1 million , and $6.4 million , respectively. Cost Recovery Clauses See Note 3 to the financial statements of Gulf Power under "Retail Regulatory Matters – Cost Recovery Clauses" in Item 8 of the Form 10-K for additional information regarding Gulf Power's recovery of retail costs through various regulatory clauses and accounting orders. Gulf Power has four regulatory clauses which are approved by the Florida PSC. The balance of each regulatory clause recovery on the balance sheet follows: Regulatory Clause Balance Sheet Location June 30, December 31, 2015 (in millions) Fuel Cost Recovery Other regulatory liabilities, current $ 18 $ 18 Purchased Power Capacity Recovery Under recovered regulatory clause revenues 4 1 Environmental Cost Recovery Under recovered regulatory clause revenues 1 19 Energy Conservation Cost Recovery Other regulatory liabilities, current — 4 Mississippi Power Energy Efficiency See Note 3 to the financial statements of Mississippi Power under "Retail Regulatory Matters – Energy Efficiency" in Item 8 of the Form 10-K for additional information regarding Mississippi Power's energy efficiency programs. On May 3, 2016, the Mississippi PSC issued an order approving the annual Energy Efficiency Cost Rider Compliance filing, which included an anticipated reduction of $2 million in retail revenues for the year ending December 31, 2016. Performance Evaluation Plan See Note 3 to the financial statements of Mississippi Power under "Retail Regulatory Matters – Performance Evaluation Plan" in Item 8 of the Form 10-K for additional information regarding Mississippi Power's base rates. On April 1, 2016, Mississippi Power submitted its annual PEP lookback filing for 2015, which reflected the need for a $5 million surcharge to be recovered from customers. The filing has been suspended for review by the Mississippi PSC. On July 12, 2016, Mississippi Power submitted its annual projected PEP filing for 2016 which indicated no change in rates. The ultimate outcome of these matters cannot be determined at this time. Fuel Cost Recovery See Note 3 to the financial statements of Mississippi Power under "Retail Regulatory Matters – Fuel Cost Recovery" in Item 8 of the Form 10-K for information regarding Mississippi Power's retail fuel cost recovery. At June 30, 2016 , the amount of over-recovered retail fuel costs included on Mississippi Power's Condensed Balance Sheet was $7

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS As of June 30, 2016 , assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using As of June 30, 2016: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives $ — $ 36 $ — $ — $ 36 Interest rate derivatives — 27 — — 27 Nuclear decommissioning trusts (a) 642 917 — 18 1,577 Cash equivalents 1,014 — — — 1,014 Other investments 9 — 1 — 10 Total $ 1,665 $ 980 $ 1 $ 18 $ 2,664 Liabilities: Energy-related derivatives $ — $ 110 $ — $ — $ 110 Interest rate derivatives — 7 — — 7 Foreign currency derivatives — 38 — — 38 Total $ — $ 155 $ — $ — $ 155 Alabama Power Assets: Energy-related derivatives $ — $ 10 $ — $ — $ 10 Nuclear decommissioning trusts (b) Domestic equity 363 67 — — 430 Foreign equity 46 47 — — 93 U.S. Treasury and government agency securities — 24 — — 24 Corporate bonds 21 142 — — 163 Mortgage and asset backed securities — 22 — — 22 Private Equity — — — 18 18 Other — 8 — — 8 Cash equivalents 210 — — — 210 Total $ 640 $ 320 $ — $ 18 $ 978 Liabilities: Energy-related derivatives $ — $ 22 $ — $ — $ 22 Fair Value Measurements Using As of June 30, 2016: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Georgia Power Assets: Energy-related derivatives $ — $ 15 $ — $ — $ 15 Interest rate derivatives — 14 — — 14 Nuclear decommissioning trusts (b) (c) Domestic equity 187 1 — — 188 Foreign equity — 116 — — 116 U.S. Treasury and government agency securities — 109 — — 109 Municipal bonds — 57 — — 57 Corporate bonds — 159 — — 159 Mortgage and asset backed securities — 159 — — 159 Other 25 6 — — 31 Cash equivalents 90 — — — 90 Total $ 302 $ 636 $ — $ — $ 938 Liabilities: Energy-related derivatives $ — $ 5 $ — $ — $ 5 Gulf Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Cash equivalents 20 — — — 20 Total $ 20 $ 2 $ — $ — $ 22 Liabilities: Energy-related derivatives $ — $ 55 $ — $ — $ 55 Interest rate derivatives — 7 — — 7 Total $ — $ 62 $ — $ — $ 62 Mississippi Power Assets: Energy-related derivatives $ — $ 1 $ — $ — $ 1 Cash equivalents 102 — — — 102 Total $ 102 $ 1 $ — $ — $ 103 Liabilities: Energy-related derivatives $ — $ 23 $ — $ — $ 23 Fair Value Measurements Using As of June 30, 2016: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Power Assets: Energy-related derivatives $ — $ 8 $ — $ — $ 8 Cash equivalents 449 — — — 449 Total $ 449 $ 8 $ — $ — $ 457 Liabilities: Energy-related derivatives $ — $ 5 $ — $ — $ 5 Foreign currency derivatives — 38 — — 38 Total $ — $ 43 $ — $ — $ 43 (a) For additional detail, see the nuclear decommissioning trusts sections for Alabama Power and Georgia Power in this table. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. (c) Includes the investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. As of June 30, 2016 , approximately $46 million of the fair market value of Georgia Power's nuclear decommissioning trust funds' securities were on loan to creditors under the funds' managers' securities lending program. Southern Company, Alabama Power, and Georgia Power continue to elect the option to fair value investment securities held in the nuclear decommissioning trust funds. The fair value of the funds at Southern Company, including reinvested interest and dividends and excluding the funds' expenses, increased by $28 million and $48 million , respectively, for the three and six months ended June 30, 2016 , and decreased by $1 million and increased by $31 million , respectively, for the three and six months ended June 30, 2015 . Alabama Power recorded an increase in fair value of $29 million and $40 million , respectively, for the three and six months ended June 30, 2016 and $5 million and $19 million , respectively, for the three and six months ended June 30, 2015 as a change in regulatory liabilities related to its AROs. Georgia Power recorded a decrease in fair value of $1 million and an increase of $8 million , respectively, for the three and six months ended June 30, 2016 and a decrease in fair value of $6 million and an increase in fair value of $12 million , respectively, for the three and six months ended June 30, 2015 as a change in its regulatory asset related to its AROs. Valuation Methodologies The energy-related derivatives primarily consist of over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflect the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflect the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note (H) for additional information on how these derivatives are used. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. For fair value measurements of the investments within the nuclear decommissioning trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. See Note 1 to the financial statements of Southern Company, Alabama Power, and Georgia Power under "Nuclear Decommissioning" in Item 8 of the Form 10-K for additional information. "Other investments" include investments that are not traded in the open market. The fair value of these investments have been determined based on market factors including comparable multiples and the expectations regarding cash flows and business plan executions. As of June 30, 2016 , the fair value measurements of private equity investments held in the nuclear decommissioning trust that are calculated at net asset value per share (or its equivalent) as a practical expedient, as well as the nature and risks of those investments, were as follows: As of June 30, 2016: Fair Value Unfunded Commitments Redemption Frequency Redemption Notice Period (in millions) Southern Company $ 18 $ 28 Not Applicable Not Applicable Alabama Power $ 18 $ 28 Not Applicable Not Applicable Private equity funds include a fund-of-funds that invests in high-quality private equity funds across several market sectors, a fund that invests in real estate assets, and a fund that acquires companies to create resale value. Private equity funds do not have redemption rights. Distributions from these funds will be received as the underlying investments in the funds are liquidated. Liquidations are expected to occur at various times over the next ten years . As of June 30, 2016 , other financial instruments for which the carrying amount did not equal fair value were as follows: Carrying Amount Fair Value (in millions) Long-term debt, including securities due within one year: Southern Company $ 37,953 $ 40,992 Alabama Power $ 7,090 $ 7,940 Georgia Power $ 10,603 $ 11,881 Gulf Power $ 1,182 $ 1,275 Mississippi Power $ 2,983 $ 2,967 Southern Power $ 4,332 $ 4,523 The fair values are determined using Level 2 measurements and are based on quoted market prices for the same or similar issues or on the current rates available to the registrants.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2016
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS' EQUITY Earnings per Share For Southern Company, the only difference in computing basic and diluted earnings per share is attributable to awards outstanding under the stock option and performance share plans. See Note 8 to the financial statements of Southern Company in Item 8 of the Form 10-K for information on the stock option and performance share plans. The effect of both stock options and performance share award units was determined using the treasury stock method. Shares used to compute diluted earnings per share were as follows: Three Months Ended June 30, 2016 Three Months Ended June 30, 2015 Six Months Ended June 30, 2016 Six Months Ended June 30, 2015 (in millions) As reported shares 934 909 925 910 Effect of options and performance share award units 6 3 6 4 Diluted shares 940 912 931 914 Stock options and performance share award units that were not included in the diluted earnings per share calculation because they were anti-dilutive were immaterial for the three and six months ended June 30, 2016 , respectively, and were 15 million and 1 million for the three and six months ended June 30, 2015 , respectively. Changes in Stockholders' Equity The following table presents year-to-date changes in stockholders' equity of Southern Company: Number of Common Shares Common Preferred and Preference Stock of Subsidiaries Total Issued Treasury Noncontrolling Interests (*) (in thousands) (in millions) Balance at December 31, 2015 915,073 (3,352 ) $ 20,592 $ 609 $ 781 $ 21,982 Consolidated net income attributable to Southern Company — — 1,097 — — 1,097 Other comprehensive income (loss) — — (117 ) — — (117 ) Stock issued 27,297 2,599 1,383 — — 1,383 Stock-based compensation — — 82 — — 82 Cash dividends on common stock — — (1,023 ) — — (1,023 ) Contributions from noncontrolling interests — — — — 169 169 Distributions to noncontrolling interests — — — — (10 ) (10 ) Purchase of membership interests from noncontrolling interests — — — — (129 ) (129 ) Net income attributable to noncontrolling interests — — — — 11 11 Other — (19 ) 1 — — 1 Balance at June 30, 2016 942,370 (772 ) $ 22,015 $ 609 $ 822 $ 23,446 Balance at December 31, 2014 908,502 (725 ) $ 19,949 $ 756 $ 221 $ 20,926 Consolidated net income attributable to Southern Company — — 1,138 — — 1,138 Other comprehensive income (loss) — — 7 — — 7 Stock issued 3,222 — 117 — — 117 Stock-based compensation — — 66 — — 66 Stock repurchased, at cost — (2,599 ) (115 ) — — (115 ) Cash dividends on common stock — — (972 ) — — (972 ) Preference stock redemption — — — (150 ) — (150 ) Contributions from noncontrolling interests — — — — 135 135 Distributions to noncontrolling interests — — — — (5 ) (5 ) Net income attributable to noncontrolling interests — — — — 4 4 Other — 25 (8 ) 3 — (5 ) Balance at June 30, 2015 911,724 (3,299 ) $ 20,182 $ 609 $ 355 $ 21,146 (*) Primarily related to Southern Power Company.

Financing

Financing	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
FINANCING	FINANCING Bank Credit Arrangements Bank credit arrangements provide liquidity support to the registrants' commercial paper borrowings and the traditional electric operating companies' pollution control revenue bonds. The amount of variable rate pollution control revenue bonds outstanding requiring liquidity support as of June 30, 2016 was approximately $1.9 billion (comprised of approximately $890 million at Alabama Power, $868 million at Georgia Power, $82 million at Gulf Power, and $40 million at Mississippi Power). In addition, at June 30, 2016 , the traditional electric operating companies had approximately $320 million (comprised of approximately $87 million at Alabama Power, $212 million at Georgia Power, and $21 million at Gulf Power) of fixed rate pollution control revenue bonds outstanding that were required to be reoffered within the next 12 months. See Note 6 to the financial statements of each registrant under "Bank Credit Arrangements" in Item 8 of the Form 10-K and " Financing Activities " herein for additional information. The following table outlines the committed credit arrangements by company as of June 30, 2016 : Expires Executable Term Loans Due Within One Year Company 2016 2017 2018 2020 Total Unused One Year Two Years Term Out No Term Out (in millions) (in millions) (in millions) (in millions) Southern Company (a) $ — $ — $ 1,000 $ 1,250 $ 2,250 $ 2,250 $ — $ — $ — $ — Alabama Power 3 32 500 800 1,335 1,335 — — — 35 Georgia Power — — — 1,750 1,750 1,732 — — — — Gulf Power 75 40 165 — 280 280 45 — 45 70 Mississippi Power 115 60 — — 175 150 — 15 15 160 Southern Power Company (b) — — — 600 600 560 — — — — Other 25 45 — 40 110 80 20 — 20 50 Total $ 218 $ 177 $ 1,665 $ 4,440 $ 6,500 $ 6,387 $ 65 $ 15 $ 80 $ 315 (a) On May 24, 2016, the $8.1 billion Bridge Agreement to provide Merger financing, to the extent necessary, was terminated. (b) Excluding its subsidiaries. See " Southern Power Project Credit Facilities " below and Note (I) under " Southern Power " for additional information. Subject to applicable market conditions, Southern Company and its subsidiaries expect to renew or replace their bank credit arrangements as needed, prior to expiration. In connection therewith, Southern Company and its subsidiaries may extend the maturity dates and/or increase or decrease the lending commitments thereunder. Southern Power Project Credit Facilities In connection with the construction of solar facilities by RE Tranquillity LLC, RE Roserock LLC, and RE Garland Holdings LLC, indirect subsidiaries of Southern Power, each subsidiary entered into separate credit agreements (Project Credit Facilities), which are non-recourse to Southern Power (other than the subsidiary party to the agreement). Each Project Credit Facility provides (a) a senior secured construction loan credit facility, (b) a senior secured bridge loan facility, and (c) a senior secured letter of credit facility that is secured by the membership interests of the respective project company. Proceeds from the Project Credit Facilities are being used to finance project costs related to the respective solar facilities currently under construction. Each Project Credit Facility is secured by the assets of the applicable project subsidiary and membership interests of the applicable project subsidiary. The table below summarizes each Project Credit Facility as of June 30, 2016 . Project Maturity Date Construction Loan Facility Bridge Loan Facility Loan Facility Total Total Loan Facility Undrawn Letter of Credit Facility Total Letter of Credit Facility Undrawn (in millions) Tranquillity Earlier of PPA COD or December 31, 2016 $ 86 $ 172 $ 258 $ 19 $ 77 $ 26 Roserock Earlier of PPA COD or November 30, 2016 63 180 243 34 23 16 Garland Earlier of PPA COD or November 30, 2016 86 308 394 73 49 23 Total $ 235 $ 660 $ 895 $ 126 $ 149 $ 65 The Project Credit Facilities had total amounts outstanding as of June 30, 2016 of $769 million at a weighted average interest rate of 2.02% . For the three-month period ended June 30, 2016 , these credit agreements had a maximum amount outstanding of $769 million and an average amount outstanding of $586 million at a weighted average interest rate of 2.03% . Financing Activities The following table outlines the long-term debt financing activities for Southern Company and its subsidiaries for the first six months of 2016 : Company Senior Note Issuances Senior Note Maturities and Redemptions Revenue Other Long-Term Debt Issuances Other Long-Term Debt Redemptions and Maturities (a) (in millions) Southern Company $ 8,500 $ — $ — $ — $ — Alabama Power 400 200 — 45 — Georgia Power 650 500 4 300 3 Gulf Power — 125 — — — Mississippi Power — — — 1,100 651 Southern Power 1,241 — — 2 4 Other — — — — 10 Elimination (b) — — — (200 ) (225 ) Total $ 10,791 $ 825 $ 4 $ 1,247 $ 443 (a) Includes reductions in capital lease obligations resulting from cash payments under capital leases. (b) Intercompany loans from Southern Company to Mississippi Power eliminated in Southern Company's Consolidated Financial Statements. Southern Company In May 2016, Southern Company issued the following series of senior notes for an aggregate principal amount of $8.5 billion : • $0.5 billion of 1.55% Senior Notes due July 1, 2018; • $1.0 billion of 1.85% Senior Notes due July 1, 2019; • $1.5 billion of 2.35% Senior Notes due July 1, 2021; • $1.25 billion of 2.95% Senior Notes due July 1, 2023; • $1.75 billion of 3.25% Senior Notes due July 1, 2026; • $0.5 billion of 4.25% Senior Notes due July 1, 2036; and • $2.0 billion of 4.40% Senior Notes due July 1, 2046. The net proceeds were used to fund a portion of the Merger and related transaction costs and for other general corporate purposes. Alabama Power In January 2016, Alabama Power issued $400 million aggregate principal amount of Series 2016A 4.30% Senior Notes due January 2, 2046. The proceeds were used to repay at maturity $200 million aggregate principal amount of Alabama Power's Series FF 5.20% Senior Notes due January 15, 2016 and for general corporate purposes, including Alabama Power's continuous construction program. In March 2016, Alabama Power entered into three bank term loan agreements with maturity dates of March 2021, in an aggregate principal amount of $45 million , one of which bears interest at 2.38% per annum and two of which bear interest based on three-month LIBOR. Georgia Power In March 2016, Georgia Power issued $325 million aggregate principal amount of Series 2016A 3.25% Senior Notes due April 1, 2026 and $325 million aggregate principal amount of Series 2016B 2.40% Senior Notes due April 1, 2021. An amount equal to the proceeds from the Series 2016A 3.25% Senior Notes due April 1, 2026 will be allocated to eligible green expenditures, including financing of or investments in solar power generation facilities or electric vehicle charging infrastructure, or payments under PPAs served by solar power or wind generation facilities. The proceeds from the Series 2016B 2.40% Senior Notes due April 1, 2021 were used to repay at maturity $250 million aggregate principal amount of Georgia Power's Series 2013B Floating Rate Senior Notes due March 15, 2016, to repay a portion of Georgia Power's short-term indebtedness, and for general corporate purposes, including Georgia Power's continuous construction program. In June 2016, Georgia Power made additional borrowings under the FFB Credit Facility in an aggregate principal amount of $300 million . The interest rate applicable to the $300 million principal amount is 2.571% for an interest period that extends to the final maturity date of February 20, 2044. The proceeds were used to reimburse Georgia Power for Eligible Project Costs relating to the construction of Plant Vogtle Units 3 and 4. Gulf Power In May 2016, Gulf Power redeemed $125 million aggregate principal amount of its Series 2011A 5.75% Senior Notes due June 1, 2051. Also in May 2016, Gulf Power entered into an 11 -month floating rate bank loan bearing interest based on one-month LIBOR. This short-term loan was for $100 million aggregate principal amount and the proceeds were used to repay existing indebtedness and for working capital and other general corporate purposes. Mississippi Power In January 2016, Mississippi Power issued a floating rate promissory note to Southern Company in an aggregate principal amount of up to $275 million , which matures on December 1, 2017, bearing interest based on one-month LIBOR. As of June 30, 2016 , Mississippi Power had borrowed $100 million under this promissory note with a $50 million draw occurring on each of January 29, 2016 and March 14, 2016. In addition, on January 19, 2016, Mississippi Power borrowed $100 million from Southern Company pursuant to a promissory note issued in November 2015. On June 27, 2016, Mississippi Power received a capital contribution from Southern Company of $225 million , the proceeds of which were used to repay to Southern Company a portion of the existing promissory note issued in November 2015. As of June 30, 2016, the amount of outstanding promissory notes to Southern Company totaled $551 million . On March 8, 2016, Mississippi Power entered into an unsecured term loan agreement with a syndicate of financial institutions for an aggregate amount of $1.2 billion to repay existing indebtedness and for other general corporate purposes. Mississippi Power borrowed $900 million under the term loan agreement and has the right to borrow the remaining $300 million on or before October 15, 2016, upon satisfaction of certain customary conditions. Mississippi Power used the initial proceeds to repay $900 million in maturing bank notes on March 8, 2016 and expects the remaining $300 million to be used to repay senior notes maturing in October 2016. The term loan pursuant to this agreement matures on April 1, 2018 and bears interest based on one-month LIBOR. In June 2016, Mississippi Power renewed a $10 million short-term note, which matures on June 30, 2017, bearing interest based on three-month LIBOR. Southern Power During the six months ended June 30, 2016 , Southern Power's subsidiaries borrowed an additional $632 million pursuant to the Project Credit Facilities at a weighted average interest rate of 2.00% . In addition, Southern Power's subsidiaries issued $16 million in letters of credit. In June 2016, Southern Power issued €600 million aggregate principal amount of Series 2016A 1.00% Senior Notes due June 20, 2022 and €500 million aggregate principal amount of Series 2016B 1.85% Senior Notes due June 20, 2026. The proceeds will be allocated to renewable energy generation projects. Southern Power's obligations under its euro-denominated fixed-rate notes were effectively converted to fixed-rate U.S. dollars at issuance through cross-currency swaps, removing foreign currency exchange risk associated with the interest and principal payments. See Note (H) under " Foreign Currency Derivatives " for additional information.

Retirement Benefits

Retirement Benefits	6 Months Ended
	Jun. 30, 2016
Compensation and Retirement Disclosure [Abstract]
RETIREMENT BENEFITS	RETIREMENT BENEFITS Southern Company has a defined benefit, trusteed, pension plan covering substantially all employees. The qualified pension plan is funded in accordance with requirements of the Employee Retirement Income Security Act of 1974, as amended. No mandatory contributions to the qualified pension plan are anticipated for the year ending December 31, 2016 . Southern Company also provides certain defined benefit pension plans for a selected group of management and highly compensated employees. Benefits under these non-qualified pension plans are funded on a cash basis. In addition, Southern Company provides certain medical care and life insurance benefits for retired employees through other postretirement benefit plans. The traditional electric operating companies fund related other postretirement trusts to the extent required by their respective regulatory commissions. See Note 2 to the financial statements of Southern Company, Alabama Power, Georgia Power, Gulf Power, and Mississippi Power in Item 8 of the Form 10-K for additional information. Components of the net periodic benefit costs for the three and six months ended June 30, 2016 and 2015 were as follows: Pension Plans Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Three Months Ended June 30, 2016 Service cost $ 62 $ 15 $ 18 $ 3 $ 3 Interest cost 101 24 34 4 5 Expected return on plan assets (187 ) (46 ) (65 ) (8 ) (8 ) Amortization: Prior service costs 3 — 2 1 — Net (gain)/loss 37 10 13 1 1 Net cost $ 16 $ 3 $ 2 $ 1 $ 1 Six Months Ended June 30, 2016 Service cost $ 124 $ 29 $ 35 $ 6 $ 6 Interest cost 201 48 68 9 10 Expected return on plan assets (374 ) (92 ) (129 ) (17 ) (17 ) Amortization: Prior service costs 7 1 3 1 — Net (gain)/loss 75 20 27 3 3 Net cost $ 33 $ 6 $ 4 $ 2 $ 2 Three Months Ended June 30, 2015 Service cost $ 64 $ 15 $ 18 $ 3 $ 3 Interest cost 111 27 39 5 6 Expected return on plan assets (181 ) (44 ) (63 ) (8 ) (9 ) Amortization: Prior service costs 7 1 2 — 1 Net (gain)/loss 54 13 19 2 2 Net cost $ 55 $ 12 $ 15 $ 2 $ 3 Six Months Ended June 30, 2015 Service cost $ 128 $ 30 $ 36 $ 6 $ 6 Interest cost 222 53 77 10 11 Expected return on plan assets (362 ) (89 ) (126 ) (16 ) (17 ) Amortization: Prior service costs 13 3 5 — 1 Net (gain)/loss 108 27 38 5 5 Net cost $ 109 $ 24 $ 30 $ 5 $ 6 Postretirement Benefits Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Three Months Ended June 30, 2016 Service cost $ 6 $ 2 $ 1 $ 1 $ 1 Interest cost 17 4 7 — 1 Expected return on plan assets (14 ) (7 ) (5 ) (1 ) (1 ) Amortization: Prior service costs 1 1 1 — — Net (gain)/loss 4 1 2 — — Net cost $ 14 $ 1 $ 6 $ — $ 1 Six Months Ended June 30, 2016 Service cost $ 11 $ 3 $ 3 $ 1 $ 1 Interest cost 35 9 15 1 2 Expected return on plan assets (28 ) (13 ) (11 ) (1 ) (1 ) Amortization: Prior service costs 3 2 1 — — Net (gain)/loss 7 1 4 — — Net cost $ 28 $ 2 $ 12 $ 1 $ 2 Three Months Ended June 30, 2015 Service cost $ 5 $ 2 $ 1 $ — $ 1 Interest cost 20 5 9 1 1 Expected return on plan assets (14 ) (7 ) (6 ) (1 ) (1 ) Amortization: Prior service costs 1 — — — — Net (gain)/loss 4 1 3 — — Net cost $ 16 $ 1 $ 7 $ — $ 1 Six Months Ended June 30, 2015 Service cost $ 11 $ 3 $ 3 $ — $ 1 Interest cost 39 10 17 2 2 Expected return on plan assets (29 ) (13 ) (12 ) (1 ) (1 ) Amortization: Prior service costs 2 1 — — — Net (gain)/loss 9 1 6 — — Net cost $ 32 $ 2 $ 14 $ 1 $ 2

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES See Note 5 to the financial statements of each registrant in Item 8 of the Form 10-K for additional tax information. Current and Deferred Income Taxes Tax Credit Carryforwards Southern Company has federal ITC and PTC carryforwards totaling $801 million and $16 million , respectively, at June 30, 2016 (comprised primarily of $784 million and $16 million of ITC and PTC carryforwards, respectively, at Southern Power). These ITC and PTC carryforwards increased from $554 million and $1 million , respectively, as of December 31, 2015 (comprised primarily of $551 million and $1 million of ITC and PTC carryforwards, respectively, at Southern Power). Additionally, Southern Company has $208 million of state ITC carryforwards for the state of Georgia as of June 30, 2016 , compared to $188 million at December 31, 2015. The federal ITC carryforwards as of June 30, 2016 begin expiring in 2034 but are expected to be utilized by the end of 2021. The PTC carryforwards as of June 30, 2016 begin expiring in 2035 but are expected to be utilized by the end of 2020. The state ITC carryforwards for the state of Georgia as of June 30, 2016 expire between 2020 and 2026 but are expected to be fully utilized by the end of 2022. Effective Tax Rate Southern Company Southern Company's effective tax rate is typically lower than the statutory rate due to employee stock plans' dividend deduction, non-taxable AFUDC equity, and federal income tax benefits from ITCs and PTCs. Southern Company's effective tax rate was 30.4% for the six months ended June 30, 2016 compared to 32.9% for the corresponding period in 2015 . The effective tax rate decrease was primarily due to increased federal income tax benefits from ITCs and PTCs at Southern Power and increased tax benefits related to the estimated probable losses on Mississippi Power's construction of the Kemper IGCC, partially offset by the impact of additional state income tax benefits recognized in 2015 . Mississippi Power Mississippi Power's effective tax rate (benefit rate) was (205.6)% for the six months ended June 30, 2016 compared to 19.0% for the corresponding period in 2015 . The effective tax rate decrease was primarily due to increased tax benefits related to the estimated probable losses on construction of the Kemper IGCC. Southern Power Southern Power's effective tax rate (benefit rate) was (74.0)% for the six months ended June 30, 2016 compared to 13.7% for the corresponding period in 2015 . The effective tax rate decrease was primarily due to increased federal income tax benefits from ITCs related to solar projects expected to be placed in service in 2016 and additional PTCs related to wind projects in 2016 compared to 2015 . Unrecognized Tax Benefits See Note 5 to the financial statements of each registrant under "Unrecognized Tax Benefits" in Item 8 of the Form 10-K for additional information. Changes during 2016 for unrecognized tax benefits were as follows: Mississippi Power Southern Power Southern Company (in millions) Unrecognized tax benefits as of December 31, 2015 $ 421 $ 8 $ 433 Tax positions from current periods — 9 10 Balance as of June 30, 2016 $ 421 $ 17 $ 443 The tax positions from current periods primarily relate to federal income tax benefits from ITCs impacting the estimated annual effective tax rate for interim reporting purposes. The impact on the effective tax rate, if recognized, is as follows: As of June 30, 2016 As of December 31, 2015 Mississippi Power Southern Power Southern Company Southern Company (in millions) Tax positions impacting the effective tax rate $ (2 ) $ 17 $ 20 $ 10 Tax positions not impacting the effective tax rate 423 — 423 423 Balance of unrecognized tax benefits $ 421 $ 17 $ 443 $ 433 The tax positions impacting the effective tax rate primarily relate to federal income tax benefits from ITCs. The tax positions not impacting the effective tax rate relate to deductions for Kemper IGCC-related research and experimental (R&E) expenditures. See " Section 174 Research and Experimental Deduction " below for additional information. These amounts are presented on a gross basis without considering the related federal or state income tax impact. Accrued interest for all tax positions other than Section 174 R&E deductions disclosed below was immaterial for all periods presented. All of the registrants classify interest on tax uncertainties as interest expense. None of the registrants accrued any penalties on uncertain tax positions. It is reasonably possible that the amount of the unrecognized tax benefits could change within 12 months . The settlement of federal and state audits could impact the balances significantly. At this time, an estimate of the range of reasonably possible outcomes cannot be determined. The IRS has finalized its audits of Southern Company's consolidated federal income tax returns through 2012. Southern Company has filed its 2013 and 2014 federal income tax returns and has received partial acceptance letters from the IRS; however, the IRS has not finalized its audits. Southern Company is a participant in the Compliance Assurance Process of the IRS. The audits for the Southern Company's state income tax returns have either been concluded, or the statute of limitations has expired, for years prior to 2011. Section 174 Research and Experimental Deduction Southern Company has reflected deductions for R&E expenditures related to the Kemper IGCC in its federal income tax calculations since 2013 and has filed amended federal income tax returns for 2008 through 2013 to also include such deductions. The Kemper IGCC is based on first-of-a-kind technology, and Southern Company and Mississippi Power believe that a significant portion of the plant costs qualify as deductible R&E expenditures under Internal Revenue Code Section 174. The IRS is currently reviewing the underlying support for the deduction, but has not completed its audit of these expenditures. Due to the uncertainty related to this tax position, Southern Company and Mississippi Power had related unrecognized tax benefits associated with these R&E deductions of approximately $423 million and associated interest of $15 million as of June 30, 2016 . The ultimate outcome of this matter cannot be determined at this time.

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES	DERIVATIVES Southern Company, the traditional electric operating companies, and Southern Power are exposed to market risks, primarily commodity price risk and interest rate risk and occasionally foreign currency risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a gross basis. See Note (C) for additional information. In the statements of cash flows, the cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. The cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with classification of the hedged interest or principal, respectively. Energy-Related Derivatives The traditional electric operating companies and Southern Power enter into energy-related derivatives to hedge exposures to electricity, gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies have limited exposure to market volatility in commodity fuel prices and prices of electricity. Each of the traditional electric operating companies manages fuel-hedging programs, implemented per the guidelines of their respective state PSCs, through the use of financial derivative contracts, which is expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in commodity fuel prices and prices of electricity because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted wholesale generating capacity is used to sell electricity. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges — Energy-related derivative contracts which are designated as regulatory hedges relate primarily to the traditional electric operating companies' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through the respective fuel cost recovery clauses. • Cash Flow Hedges — Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in OCI before being recognized in the statements of income in the same period as the hedged transactions are reflected in earnings. • Not Designated — Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric industry. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. At June 30, 2016 , the net volume of energy-related derivative contracts for natural gas positions for the Southern Company system, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Purchased mmBtu Longest Hedge Date Longest Non-Hedge Date (in millions) Southern Company 250 2020 2016 Alabama Power 60 2019 — Georgia Power 82 2019 — Gulf Power 66 2020 — Mississippi Power 29 2019 — Southern Power 13 2017 2016 In addition to the volumes discussed in the above table, the traditional electric operating companies and Southern Power enter into physical natural gas supply contracts that provide the option to sell back excess gas due to operational constraints. The maximum expected volume of natural gas subject to such a feature is 3 million mmBtu for Southern Company and Georgia Power. For cash flow hedges, the amounts expected to be reclassified from accumulated OCI to earnings for the next 12-month period ending June 30, 2017 are immaterial for all registrants. Interest Rate Derivatives Southern Company and certain subsidiaries may also enter into interest rate derivatives to hedge exposure to changes in interest rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the effective portion of the derivatives' fair value gains or losses is recorded in OCI and is reclassified into earnings at the same time the hedged transactions affect earnings, with any ineffectiveness recorded directly to earnings. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings, providing an offset, with any difference representing ineffectiveness. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. At June 30, 2016 , the following interest rate derivatives were outstanding: Notional Amount Interest Rate Received Weighted Average Interest Rate Paid Hedge Maturity Date Fair Value (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Gulf Power $ 80 3-month 2.32% December 2026 $ (7 ) Cash Flow Hedges of Existing Debt Southern Company 8 (d) 3-month 1.73% June 2020 — Southern Company 3 (d) 3-month 1.73% June 2020 — Georgia Power 200 3-month 1.01% August 2016 — Fair Value Hedges of Existing Debt Southern Company 250 1.30% 3-month August 2017 2 Southern Company 300 2.75% 3-month June 2020 11 Georgia Power 250 5.40% 3-month June 2018 3 Georgia Power 200 4.25% 3-month December 2019 6 Georgia Power 500 1.95% 3-month December 2018 5 Derivatives not Designated as Hedges Southern Power 65 (a,d) 3-month 2.50% October 2016 (e) — Southern Power 47 (b,d) 3-month 2.21% October 2016 (e) — Southern Power 65 (c,d) 3-month 2.21% November 2016 (f) — Total $ 1,968 $ 20 (a) Swaption at RE Tranquillity LLC. See Note 12 to the financial statements of Southern Company and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information. (b) Swaption at RE Roserock LLC. See Note 12 to the financial statements of Southern Company and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information. (c) Swaption at RE Garland Holdings LLC. See Note 12 to the financial statements of Southern Company and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information. (d) Amortizing notional amount. (e) Represents the mandatory settlement date. Settlement will be based on a 15 -year amortizing swap. (f) Represents the mandatory settlement date. Settlement will be based on a 12 -year amortizing swap. The estimated pre-tax gains (losses) expected to be reclassified from accumulated OCI to interest expense for the next 12-month period ending June 30, 2017 are immaterial for all registrants. Southern Company and certain subsidiaries have deferred gains and losses that are expected to be amortized into earnings through 2046 . Foreign Currency Derivatives Southern Company and certain subsidiaries may also enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the effective portion of the derivatives' fair value gains or losses is recorded in OCI and is reclassified into earnings at the same time that the hedged transactions affect earnings, including currency gains or losses arising from changes in the U.S. currency exchange rates. Any ineffectiveness is recorded directly to earnings. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. At June 30, 2016, the following foreign currency derivatives were outstanding: Pay Notional Pay Rate Receive Notional Receive Rate Hedge Fair Value (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 677 2.95% € 600 1.00% June 2022 $ (17 ) Southern Power 564 3.78% 500 1.85% June 2026 (21 ) Total $ 1,241 € 1,100 $ (38 ) The estimated pre-tax gains (losses) that will be reclassified from accumulated OCI to earnings for the next 12-month period ending June 30, 2017 are $(24) million for Southern Company and Southern Power. Derivative Financial Statement Presentation and Amounts At June 30, 2016 , the fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: Asset Derivatives at June 30, 2016 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets $ 12 $ 5 $ 6 $ 1 $ — Other deferred charges and assets 16 5 9 1 1 Total derivatives designated as hedging instruments for regulatory purposes $ 28 $ 10 $ 15 $ 2 $ 1 N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets $ 5 $ — $ — $ — $ — $ 5 Other deferred charges and assets 1 — — — — 1 Interest rate derivatives: Other current assets 11 — 6 — — — Other deferred charges and assets 16 — 8 — — — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 33 $ — $ 14 $ — $ — $ 6 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets $ 2 $ — $ — $ — $ — $ 2 Total asset derivatives $ 63 $ 10 $ 29 $ 2 $ 1 $ 8 Liability Derivatives at June 30, 2016 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Liabilities from risk management activities (*) $ 61 $ 17 $ 4 $ 25 $ 15 Other deferred credits and liabilities 44 5 1 30 8 Total derivatives designated as hedging instruments for regulatory purposes $ 105 $ 22 $ 5 $ 55 $ 23 N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Liabilities from risk management activities (*) $ 3 $ — $ — $ — $ — $ 3 Other deferred credits and liabilities 1 — — — — 1 Interest rate derivatives: Liabilities from risk management activities (*) 7 — — 7 — — Foreign currency derivatives: Liabilities from risk management activities (*) 24 — — — — 24 Other deferred credits and liabilities 14 — — — — 14 Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 49 $ — $ — $ 7 $ — $ 42 Derivatives not designated as hedging instruments Energy-related derivatives: Other current liabilities $ 1 $ — $ — $ — $ — $ 1 Total liability derivatives $ 155 $ 22 $ 5 $ 62 $ 23 $ 43 (*) Georgia Power, Mississippi Power, and Southern Power include current liabilities related to derivatives in "Other current liabilities." At December 31, 2015 , the fair value of energy-related derivatives and interest rate derivatives was reflected in the balance sheets as follows: Asset Derivatives at December 31, 2015 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets $ 3 $ 1 $ 2 $ — $ — N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets $ 3 $ — $ — $ — $ — $ 3 Interest rate derivatives: Other current assets 19 — 5 1 — — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 22 $ — $ 5 $ 1 $ — $ 3 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets $ 1 $ — $ — $ — $ — $ 1 Interest rate derivatives: Other current assets 3 — — — — 3 Total derivatives not designated as hedging instruments $ 4 $ — $ — $ — $ — $ 4 Total asset derivatives $ 29 $ 1 $ 7 $ 1 $ — $ 7 Liability Derivatives at December 31, 2015 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Liabilities from risk management activities (*) $ 130 $ 40 $ 12 $ 49 $ 29 Other deferred credits and liabilities 87 15 3 51 18 Total derivatives designated as hedging instruments for regulatory purposes $ 217 $ 55 $ 15 $ 100 $ 47 N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Liabilities from risk management activities (*) $ 2 $ — $ — $ — $ — $ 2 Interest rate derivatives: Liabilities from risk management activities 23 15 — — — — Other deferred credits and liabilities 7 — 6 — — — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 32 $ 15 $ 6 $ — $ — $ 2 Derivatives not designated as hedging instruments Energy-related derivatives: Liabilities from risk management activities (*) $ 1 $ — $ — $ — $ — $ 1 Total liability derivatives $ 250 $ 70 $ 21 $ 100 $ 47 $ 3 (*) Georgia Power, Mississippi Power, and Southern Power include current liabilities related to derivatives in "Other current liabilities." The derivative contracts of Southern Company, the traditional electric operating companies, and Southern Power are not subject to master netting arrangements or similar agreements and are reported gross on each registrant's financial statements. Some of these energy-related and interest rate derivative contracts may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Amounts related to energy-related derivative contracts, interest rate derivative contracts, and foreign currency derivative contracts at June 30, 2016 and December 31, 2015 are presented in the following tables. Derivative Contracts at June 30, 2016 Fair Value Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Assets Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 36 $ 10 $ 15 $ 2 $ 1 $ 8 Gross amounts not offset in the Balance Sheet (b) (32 ) (8 ) (4 ) (2 ) (1 ) (3 ) Net energy-related derivative assets $ 4 $ 2 $ 11 $ — $ — $ 5 Interest rate and foreign currency derivatives: Interest rate and foreign currency derivatives presented in the Balance Sheet (a) $ 27 $ — $ 14 $ — $ — $ — Gross amounts not offset in the Balance Sheet (b) (18 ) — — — — — Net interest rate and foreign currency derivative assets $ 9 $ — $ 14 $ — $ — $ — Liabilities Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 110 $ 22 $ 5 $ 55 $ 23 $ 5 Gross amounts not offset in the Balance Sheet (b) (32 ) (8 ) (4 ) (2 ) (1 ) (3 ) Net energy-related derivative liabilities $ 78 $ 14 $ 1 $ 53 $ 22 $ 2 Interest rate and foreign currency derivatives: Interest rate and foreign currency derivatives presented in the Balance Sheet (a) $ 45 $ — $ — $ 7 $ — $ 38 Gross amounts not offset in the Balance Sheet (b) (18 ) — — — — — Net interest rate and foreign currency derivative liabilities $ 27 $ — $ — $ 7 $ — $ 38 (a) None of the registrants offsets fair value amounts for multiple derivative instruments executed with the same counterparty on the balance sheets; therefore, gross and net amounts of derivative assets and liabilities presented on the balance sheets are the same. (b) Includes gross amounts subject to netting terms that are not offset on the balance sheets and any cash/financial collateral pledged or received. Derivative Contracts at December 31, 2015 Fair Value Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Assets Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 7 $ 1 $ 2 $ — $ — $ 4 Gross amounts not offset in the Balance Sheet (b) (6 ) (1 ) (2 ) — — (1 ) Net energy-related derivative assets $ 1 $ — $ — $ — $ — $ 3 Interest rate derivatives: Interest rate derivatives presented in the Balance Sheet (a) $ 22 $ — $ 5 $ 1 $ — $ 3 Gross amounts not offset in the Balance Sheet (b) (9 ) — (4 ) — — — Net interest rate derivative assets $ 13 $ — $ 1 $ 1 $ — $ 3 Liabilities Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 220 $ 55 $ 15 $ 100 $ 47 $ 3 Gross amounts not offset in the Balance Sheet (b) (6 ) (1 ) (2 ) — — (1 ) Net energy-related derivative liabilities $ 214 $ 54 $ 13 $ 100 $ 47 $ 2 Interest rate derivatives: Interest rate derivatives presented in the Balance Sheet (a) $ 30 $ 15 $ 6 $ — $ — $ — Gross amounts not offset in the Balance Sheet (b) (9 ) — (4 ) — — — Net interest rate derivative liabilities $ 21 $ 15 $ 2 $ — $ — $ — (a) None of the registrants offsets fair value amounts for multiple derivative instruments executed with the same counterparty on the balance sheets; therefore, gross and net amounts of derivative assets and liabilities presented on the balance sheets are the same. (b) Includes gross amounts subject to netting terms that are not offset on the balance sheets and any cash/financial collateral pledged or received. At June 30, 2016 and December 31, 2015 , the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet at June 30, 2016 Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Energy-related derivatives: Other regulatory assets, current $ (61 ) $ (17 ) $ (4 ) $ (25 ) $ (15 ) Other regulatory assets, deferred (44 ) (5 ) (1 ) (30 ) (8 ) Other regulatory liabilities, current (a) 12 5 6 1 — Other regulatory liabilities, deferred (b) 16 5 9 1 1 Total energy-related derivative gains (losses) $ (77 ) $ (12 ) $ 10 $ (53 ) $ (22 ) (a) Georgia Power includes other regulatory liabilities, current in other current liabilities. (b) Georgia Power includes other regulatory liabilities, deferred in other deferred credits and liabilities. Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet at December 31, 2015 Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Energy-related derivatives: Other regulatory assets, current $ (130 ) $ (40 ) $ (12 ) $ (49 ) $ (29 ) Other regulatory assets, deferred (87 ) (15 ) (3 ) (51 ) (18 ) Other regulatory liabilities, current (*) 3 1 2 — — Total energy-related derivative gains (losses) $ (214 ) $ (54 ) $ (13 ) $ (100 ) $ (47 ) (*) Georgia Power includes other regulatory liabilities, current in other current liabilities. For the three months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives and foreign currency derivatives designated as cash flow hedging instruments were as follows: Derivatives in Cash Flow Hedging Relationships Gain (Loss) Recognized in OCI on Derivative (Effective Portion) Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Statements of Income Location Amount 2016 2015 2016 2015 (in millions) (in millions) Southern Company Interest rate derivatives $ 6 $ 31 Interest expense, net of amounts capitalized $ (4 ) $ (2 ) Foreign currency derivatives (39 ) — Interest expense, net of amounts capitalized (1 ) — Other income (expense), net (20 ) — Total $ (33 ) $ 31 $ (25 ) $ (2 ) Alabama Power Interest rate derivatives $ — $ 7 Interest expense, net of amounts capitalized $ (2 ) $ (1 ) Georgia Power Interest rate derivatives $ — $ 24 Interest expense, net of amounts capitalized $ (1 ) $ (1 ) Gulf Power Interest rate derivatives $ (2 ) $ — Interest expense, net of amounts capitalized $ — $ — Southern Power Foreign currency derivatives $ (39 ) $ — Interest expense, net of amounts capitalized $ (1 ) $ — Other income (expense), net (20 ) — Total $ (39 ) $ — $ (21 ) $ — For the six months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives and foreign currency derivatives designated as cash flow hedging instruments recognized in OCI and those reclassified from accumulated OCI into earnings were as follows: Derivatives in Cash Flow Gain (Loss) Gain (Loss) Reclassified from Accumulated OCI into Statements of Income Location Amount 2016 2015 2016 2015 (in millions) (in millions) Southern Company Interest rate derivatives $ (184 ) $ 2 Interest expense, net of amounts capitalized $ (7 ) $ (4 ) Foreign currency derivatives (39 ) — Interest expense, net of amounts capitalized (1 ) — Other income (expense), net (20 ) — Total $ (223 ) $ 2 $ (28 ) $ (4 ) Alabama Power Interest rate derivatives $ (4 ) $ 1 Interest expense, net of amounts capitalized $ (3 ) $ (1 ) Georgia Power Interest rate derivatives $ — $ 1 Interest expense, net of amounts capitalized $ (2 ) $ (2 ) Gulf Power Interest rate derivatives $ (7 ) $ — Interest expense, net of amounts capitalized $ — $ — Mississippi Power Interest rate derivatives $ — $ — Interest expense, net of amounts capitalized $ (1 ) $ (1 ) Southern Power Interest rate derivatives $ — $ — Interest expense, net of amounts capitalized $ (1 ) $ — Foreign currency derivatives (39 ) — Interest expense, net of amounts capitalized (1 ) — Other income (expense), net (20 ) — Total $ (39 ) $ — $ (22 ) $ — For the three and six months ended June 30, 2016 and 2015 , the pre-tax effects of energy-related derivatives designated as cash flow hedging instruments recognized in OCI and those reclassified from accumulated OCI into earnings were immaterial for all registrants. For the three months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives designated as fair value hedging instruments were immaterial on a gross basis for all registrants. For the six months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives designated as fair value hedging instruments were as follows: Derivatives in Fair Value Hedging Relationships Gain (Loss) Derivative Category Statements of Income Location 2016 2015 (in millions) Southern Company Interest rate derivatives: Interest expense, net of amounts capitalized $ 24 $ 4 Georgia Power Interest rate derivatives: Interest expense, net of amounts capitalized $ 15 $ 2 For the three and six months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives designated as fair value hedging instruments were offset by changes to the carrying value of long-term debt. There was no material ineffectiveness recorded in earnings for any registrant for any period presented. For the three and six months ended June 30, 2016 and 2015 , the pre-tax effects of energy-related derivatives and interest rate derivatives not designated as hedging instruments were immaterial for all registrants. Contingent Features The registrants do not have any credit arrangements that would require material changes in payment schedules or terminations as a result of a credit rating downgrade. There are certain derivatives that could require collateral, but not accelerated payment, in the event of various credit rating changes of certain Southern Company subsidiaries. At June 30, 2016 , the registrants' collateral posted with their derivative counterparties was immaterial. At June 30, 2016 , the fair value of derivative liabilities with contingent features was $24 million for all registrants. The maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, were $24 million and include certain agreements that could require collateral in the event that one or more Southern Company power pool participants has a credit rating change to below investment grade. Generally, collateral may be provided by a Southern Company guaranty, letter of credit, or cash. If collateral is required, fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral are not offset against fair value amounts recognized for derivatives executed with the same counterparty. Southern Company, the traditional electric operating companies, and Southern Power are exposed to losses related to financial instruments in the event of counterparties' nonperformance. Southern Company, the traditional electric operating companies, and Southern Power only enter into agreements and material transactions with counterparties that have investment grade credit ratings by Moody's and S&P or with counterparties who have posted collateral to cover potential credit exposure. Southern Company, the traditional electric operating companies, and Southern Power have also established risk management policies and controls to determine and monitor the creditworthiness of counterparties in order to mitigate Southern Company's, the traditional electric operating companies', and Southern Power's exposure to counterparty credit risk. Therefore, Southern Company, the traditional electric operating companies, and Southern Power do not anticipate a material adverse effect on the financial statements as a result of counterparty nonperformance.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Southern Company Merger with Southern Company Gas Southern Company Gas, formerly known as AGL Resources Inc., is an energy services holding company whose primary business is the distribution of natural gas through natural gas distribution utilities. On July 1, 2016, Southern Company completed the Merger for a total purchase price of approximately $8.0 billion and Southern Company Gas became a wholly-owned, direct subsidiary of Southern Company. The Merger will be accounted for using the acquisition method of accounting whereby the assets acquired and liabilities assumed are recognized at fair value as of the acquisition date. The excess of the purchase price over the fair values of Southern Company Gas' assets and liabilities will be recorded as goodwill. The following table presents the preliminary purchase price allocation: Southern Company Gas Purchase Price June 30, 2016 (in millions) Current assets $ 1,474 Property, plant, and equipment 9,795 Goodwill 6,333 Intangible assets 436 Regulatory assets 846 Other assets 273 Current liabilities (2,205 ) Other liabilities (4,529 ) Long-term debt (4,261 ) Noncontrolling interests (160 ) Total purchase price $ 8,002 The estimated fair values noted above are preliminary and are subject to change upon finalization of the purchase accounting assessment as additional information related to the fair value of assets and liabilities becomes available. Subsequent adjustments to the preliminary purchase price allocation may have a material impact on the results of operations and financial position of Southern Company. During the three and six months ended June 30, 2016 , Southern Company recorded in its statements of income external transaction costs for financing, legal, and consulting services associated with the Merger of approximately $43.4 million and $63.3 million , respectively, of which $26.9 million and $32.9 million is included in operating expenses and $16.5 million and $30.4 million is included in other income and (expense), respectively. See Note 12 to the financial statements of Southern Company under "Southern Company – Proposed Merger with AGL Resources" in Item 8 of the Form 10-K for additional information. Acquisition of PowerSecure International, Inc. On May 9, 2016, Southern Company acquired all of the outstanding stock of PowerSecure, a leading provider of products and services in the areas of distributed generation, energy efficiency, and utility infrastructure, for $18.75 per common share in cash, resulting in an aggregate purchase price of $429 million . As a result, PowerSecure became a wholly-owned subsidiary of Southern Company. The aggregate purchase price was allocated on a preliminary basis to the assets acquired and liabilities assumed based upon the current determination of fair values at the date of acquisition. The preliminary allocation of the purchase price is as follows: PowerSecure Purchase Price June 30, 2016 (in millions) Current assets $ 174 Property, plant, and equipment 48 Goodwill 262 Intangible assets 99 Other assets 8 Current liabilities (111 ) Long-term debt, including current portion (47 ) Deferred credits and other liabilities (4 ) Total purchase price $ 429 The excess of the purchase price over the estimated fair values of the assets acquired and liabilities assumed of $262 million was recognized as goodwill, which is primarily attributable to the expected business expansion opportunities for PowerSecure. Southern Company anticipates that the majority of the value assigned to goodwill will not be deductible for tax purposes. Assumptions and estimates underlying the fair value adjustments are subject to change pending further review of the assets acquired and liabilities assumed. The preliminary valuation of identifiable intangible assets included customer relationships, trade names, patents, and backlog with estimated lives of three to 26 years. The estimated fair value measurements of identifiable intangible assets were primarily based on significant unobservable inputs (Level 3). The results of operations for PowerSecure have been included in the consolidated financial statements from the date of acquisition and are immaterial to the consolidated financial results of Southern Company. Pro forma results of operations have not been presented for the acquisition because the effects of the acquisition were immaterial to Southern Company's consolidated financial results for all periods presented. Natural Gas Pipeline Venture On July 10, 2016, Southern Company and Kinder Morgan, Inc. (Kinder Morgan) entered into a definitive agreement under which Southern Company will acquire a 50% equity interest in Southern Natural Gas Company, L.L.C. (SNG), which is the owner of a 7,600 -mile pipeline system connecting natural gas supply basins in Texas, Louisiana, Mississippi, Alabama, and the Gulf of Mexico to markets in Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and Tennessee. Southern Company expects to finance the purchase price of approximately $1.5 billion with a mix of equity and debt in a credit-supportive manner. Southern Company's investment in SNG will be accounted for under the equity method of accounting. The transaction is subject to the notification and clearance and reporting requirements under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. Southern Company and Kinder Morgan expect to complete the transaction in the third quarter or early in the fourth quarter 2016. The ultimate outcome of this matter cannot be determined at this time. Southern Power See Note 2 to the financial statements of Southern Power and Note 12 to the financial statements of Southern Company under "Southern Power" in Item 8 of the Form 10-K for additional information. During the six months ended June 30, 2016, the fair values of the assets and liabilities acquired of Garland, Garland A, Lost Hills Blackwell, Morelos, North Star, and Roserock were finalized and there were no changes. During 2016 , in accordance with its overall growth strategy, Southern Power acquired or contracted to acquire through its wholly-owned subsidiaries, Southern Renewable Partnerships, LLC or Southern Renewable Energy, Inc., the projects discussed below. Acquisition-related costs were expensed as incurred and were not material. The acquisitions do not include any contingent consideration unless specifically noted. Project Facility Resource Seller; Acquisition Date Approx. Nameplate Capacity Location Southern Power Percentage Ownership Expected/Actual COD PPA Counterparties for Plant Output PPA Contract Period (MW) Acquisitions for the Six Months Ended June 30, 2016 Calipatria Solar Solar Frontier Americas Holding LLC February 11, 2016 20 Imperial County, CA 90 % February 2016 San Diego Gas & Electric Company 20 years East Pecos Solar First Solar, Inc. March 4, 2016 120 Pecos County, TX 100 % Fourth quarter 2016 Austin Energy 15 years Grant Wind Wind Apex Clean Energy Holdings, LLC April 7, 2016 151 Grant County, OK 100 % April 2016 Western Farmers, East Texas, and Northeast Texas Electric Cooperative 20 years Passadumkeag Wind Quantum Utility Generation, LLC June 30, 2016 42 Penobscot County, ME 100 % July 2016 Western Massachusetts Electric Company 15 years Acquisitions Subsequent to June 30, 2016 Henrietta Solar SunPower Corp. July 1, 2016 102 Kings County, CA 51 % (*) July 2016 Pacific Gas and Electric Company 20 years Lamesa Solar RES America Developments Inc. July 1, 2016 102 Dawson County, TX 100 % Second quarter 2017 City of Garland, Texas 15 years Rutherford Solar Cypress Creek Renewables, LLC July 1, 2016 74 Rutherford County, NC 90 % Fourth quarter 2016 Duke Energy Carolinas, LLC 15 years (*) Southern Power owns 100% of the class A membership interests and a wholly-owned subsidiary of the seller owns 100% of the class B membership interests. Southern Power and the class B member are entitled to 51% and 49% , respectively, of all cash distributions from the project. In addition, Southern Power is entitled to substantially all of the federal tax benefits with respect to the transaction. Acquisitions During the Six Months Ended June 30, 2016 Southern Power's aggregate purchase price for the project facilities acquired during the six months ended June 30, 2016 is approximately $477 million , which includes $6 million of contingent consideration. Including the minority owner Turner Renewable Energy, LLC's (TRE) 10% ownership interest in Calipatria, the total aggregate purchase price is approximately $483 million for the project facilities acquired during the six months ended June 30, 2016. The fair values of the assets and liabilities acquired through the business combinations were recorded as follows: $426 million as CWIP, $58 million as property, plant, and equipment, $4 million as other assets, and $7 million as accounts payable; however, the allocations of the purchase price to individual assets have not been finalized. For East Pecos, which is currently under construction, total construction costs, excluding the acquisition costs, are expected to be approximately $160 million to $180 million . The ultimate outcome of this matter cannot be determined at this time. Acquisitions Subsequent to June 30, 2016 Southern Power's aggregate purchase price for acquisitions subsequent to June 30, 2016 is approximately $275 million . Including the minority owner, SunPower Corp.'s 49% ownership interest in Henrietta, and TRE's 10% ownership interest in Rutherford, the aggregate total purchase price is approximately $447 million for the project facilities acquired subsequent to June 30, 2016. The aggregate purchase price includes the assumption of $217 million in construction debt (non-recourse to Southern Power). For Lamesa and Rutherford, which are currently under construction, total aggregate construction costs, excluding the acquisition costs, are expected to be approximately $260 million to $300 million . The ultimate outcome of these matters cannot be determined at this time. Acquisition Agreements Executed but Not Yet Closed During the six months ended June 30, 2016 and subsequent to that date, Southern Power entered into agreements to acquire the following projects for an aggregate purchase price of $1.1 billion : 100% ownership interests in two wind facilities totaling 299 MWs in Texas, significantly covered with PPAs for the first 12 to 14 years of operation; a 51% ownership interest (through 100% ownership of the Class A membership interests entitling Southern Power to 51% of all cash distributions and significantly all of the federal tax benefits) in a 100 -MW solar facility in Nevada with a 20 -year PPA; and a 90.1% ownership interest in a 257 -MW wind facility in Texas significantly covered with a 12 -year PPA. These acquisitions are expected to close in the third and fourth quarters of 2016. The ultimate outcome of these matters cannot be determined at this time. The aggregate amount of revenue recognized by Southern Power related to the project facilities acquired during the six months ended June 30, 2016 included in the consolidated statement of income for year-to-date 2016 is $4 million . The aggregate amount of net income, excluding impacts of ITCs and PTCs, attributable to Southern Power related to the project facilities acquired during the six months ended June 30, 2016 included in the consolidated statement of income is immaterial. These businesses did not have operating revenues or activities prior to completion of construction and their assets being placed in service; therefore, supplemental pro forma information as though the acquisitions occurred as of the beginning of 2016 and for the comparable 2015 period is not meaningful and has been omitted. Construction Projects During the six months ended June 30, 2016 , in accordance with its overall growth strategy, Southern Power completed construction of and placed in service the Butler Solar Farm and Pawpaw solar facilities. In addition, Southern Power continued construction of the projects set forth in the table below. Through June 30, 2016 , total costs of construction incurred for the projects below were $2.7 billion , of which $1.7 billion remains in CWIP. Including the total construction costs incurred to date and the acquisition prices allocated to CWIP, total aggregate construction costs for the projects below are estimated to be approximately $3.0 billion to $3.2 billion . The ultimate outcome of these matters cannot be determined at this time. Solar Facility Seller Approx. Nameplate Capacity Location Expected/Actual COD PPA Counterparties for Plant Output PPA Contract Period (MW) Butler CERSM, LLC and Community Energy, Inc. 103 Taylor County, GA Fourth quarter 2016 Georgia Power (a) 30 years Desert Stateline (b) First Solar Development, LLC 299 (c) San Bernardino County, CA Through third quarter 2016 Southern California Edison Company (SCE) 20 years Garland and Garland A Recurrent Energy, LLC 205 Kern County, CA Fourth quarter 2016 and SCE 15 years and Roserock Recurrent Energy, LLC 160 Pecos County, TX Fourth quarter 2016 Austin Energy 20 years Sandhills N/A 146 Taylor County, GA Fourth quarter 2016 Cobb, Flint, Irwin, Middle Georgia and Sawnee Electric Membership Corporations 25 years Tranquillity Recurrent Energy, LLC 205 Fresno County, CA July 2016 Shell Energy North America (US), LP/SCE 18 years (a) Butler - Affiliate PPA approved by the FERC. (b) Desert Stateline - On March 29, 2016, Southern Power acquired an additional 15% interest in Desert Stateline. As a result, Southern Power and the class B member are entitled to 66% and 34% , respectively, of all cash distributions from Desert Stateline. In addition, Southern Power will continue to be entitled to substantially all of the federal tax benefits with respect to the transaction. Total estimated construction costs include the acquisition price allocated to CWIP; however, the allocation of the purchase price to individual assets has not been finalized. (c) Desert Stateline - The facility has a total of 299 MWs, of which 110 MWs were placed in service in the fourth quarter 2015 and 152 MWs were placed in service during the six months ended June 30, 2016. Subsequent to June 30, 2016, 37 MWs were placed in service.

Segment and Related Information

Segment and Related Information	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
SEGMENT AND RELATED INFORMATION	SEGMENT AND RELATED INFORMATION The primary business of the Southern Company system is electricity sales by the traditional electric operating companies and Southern Power. The four traditional electric operating companies – Alabama Power, Georgia Power, Gulf Power, and Mississippi Power – are vertically integrated utilities providing electric service in four Southeastern states. Southern Power constructs, acquires, owns, and manages generation assets, including renewable energy projects, and sells electricity at market-based rates in the wholesale market. Southern Company's reportable business segments are the sale of electricity by the four traditional electric operating companies and Southern Power. Revenues from sales by Southern Power to the traditional electric operating companies were $107 million and $204 million for the three and six months ended June 30, 2016 , respectively, and $85 million and $199 million for the three and six months ended June 30, 2015 , respectively. The "All Other" column includes parent Southern Company, which does not allocate operating expenses to business segments. Also, this category includes segments below the quantitative threshold for separate disclosure. These segments include products and services in the areas of distributed generation, energy efficiency, and utility infrastructure, as well as investments in telecommunications and leveraged lease projects. All other inter-segment revenues are not material. Financial data for business segments and products and services for the three and six months ended June 30, 2016 and 2015 was as follows: Electric Utilities Traditional Electric Operating Companies Southern Power Eliminations Total All Other Eliminations Consolidated (in millions) Three Months Ended June 30, 2016: Operating revenues $ 4,115 $ 373 $ (109 ) $ 4,379 $ 125 $ (45 ) $ 4,459 Segment net income (loss) (a)(b) 595 89 — 684 (68 ) (4 ) 612 Six Months Ended June 30, 2016: Operating revenues $ 7,884 $ 688 $ (212 ) $ 8,360 $ 172 $ (81 ) $ 8,451 Segment net income (loss) (a)(c) 1,059 139 — 1,198 (94 ) (7 ) 1,097 Total assets at June 30, 2016 $ 70,706 $ 11,082 $ (425 ) $ 81,363 $ 10,505 $ (995 ) $ 90,873 Three Months Ended June 30, 2015: Operating revenues $ 4,077 $ 337 $ (90 ) $ 4,324 $ 43 $ (30 ) $ 4,337 Segment net income (loss) (a)(b) 561 46 — 607 18 4 629 Six Months Ended June 30, 2015: Operating revenues $ 8,025 $ 684 $ (213 ) $ 8,496 $ 83 $ (59 ) $ 8,520 Segment net income (loss) (a)(c) 1,038 79 — 1,117 21 — 1,138 Total assets at December 31, 2015 $ 69,052 $ 8,905 $ (397 ) $ 77,560 $ 1,819 $ (1,061 ) $ 78,318 (a) Attributable to Southern Company. (b) Segment net income (loss) for the traditional electric operating companies includes pre-tax charges for estimated probable losses on the Kemper IGCC of $81 million ( $50 million after tax) and $23 million ( $14 million after tax) for the three months ended June 30, 2016 and 2015 , respectively. See Note (B) under " Integrated Coal Gasification Combined Cycle – Kemper IGCC Schedule and Cost Estimate " for additional information. (c) Segment net income (loss) for the traditional electric operating companies includes pre-tax charges for estimated probable losses on the Kemper IGCC of $134 million ( $83 million after tax) and $32 million ( $20 million after tax) for the six months ended June 30, 2016 and 2015 , respectively. See Note (B) under " Integrated Coal Gasification Combined Cycle – Kemper IGCC Schedule and Cost Estimate " for additional information. Products and Services Electric Utilities' Revenues Period Retail Wholesale Other Total (in millions) Three Months Ended June 30, 2016 $ 3,748 $ 446 $ 185 $ 4,379 Three Months Ended June 30, 2015 3,714 448 162 4,324 Six Months Ended June 30, 2016 $ 7,124 $ 842 $ 394 $ 8,360 Six Months Ended June 30, 2015 7,256 915 325 8,496

Introduction (Policies)

Introduction (Policies)	6 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	The condensed quarterly financial statements of each registrant included herein have been prepared by such registrant, without audit, pursuant to the rules and regulations of the SEC. The Condensed Balance Sheets as of December 31, 2015 have been derived from the audited financial statements of each registrant. In the opinion of each registrant's management, the information regarding such registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended June 30, 2016 and 2015 . Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations, although each registrant believes that the disclosures regarding such registrant are adequate to make the information presented not misleading. Disclosures which would substantially duplicate the disclosures in the Form 10-K and details which have not changed significantly in amount or composition since the filing of the Form 10-K are generally omitted from this Quarterly Report on Form 10-Q unless specifically required by GAAP. Therefore, these Condensed Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K. Due to the seasonal variations in the demand for energy, operating results for the periods presented are not necessarily indicative of the operating results to be expected for the full year.
Reclassification	Certain prior year data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the results of operations, financial position, or cash flows of any registrant.
Recently Issued Accounting Standards	Recently Issued Accounting Standards On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize on the balance sheet a lease liability and a right-of-use asset for all leases. ASU 2016-02 also changes the recognition, measurement, and presentation of expense associated with leases and provides clarification regarding the identification of certain components of contracts that would represent a lease. The accounting required by lessors is relatively unchanged and there is no change to the accounting for existing leveraged leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. The registrants are currently evaluating the new standard and have not yet determined its ultimate impact; however, adoption of ASU 2016-02 is expected to have a significant impact on Southern Company and the traditional electric operating companies' balance sheets. On March 30, 2016, the FASB issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09). ASU 2016-09 changes the accounting for income taxes and the cash flow presentation for share-based payment award transactions. Most significantly, entities are required to recognize all excess tax benefits and deficiencies related to the exercise or vesting of stock compensation as income tax expense or benefit in the income statement. Southern Company and the traditional electric operating companies currently recognize any excess tax benefits and deficiencies related to the exercise and vesting of stock compensation in additional paid-in capital. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016. Early adoption is permitted and Southern Company and the traditional electric operating companies intend to adopt the ASU in the fourth quarter 2016. The adoption is not expected to have a material impact on the results of operations, financial position, or cash flows of Southern Company and the traditional electric operating companies.
Asset Retirement Obligations	The cost estimates below are based on information as of June 30, 2016 using various assumptions related to closure and post-closure costs, timing of future cash outlays, inflation and discount rates, and the potential methods for complying with the Disposal of Coal Combustion Residuals from Electric Utilities final rule requirements for closure in place or by other methods. As further analysis is performed, including evaluation of the expected method of compliance, refinement of assumptions underlying the cost estimates, such as the quantities of CCR at each site, and the determination of timing, including the potential for closing ash ponds prior to the end of their currently anticipated useful life, the traditional electric operating companies expect to continue to periodically update these estimates. As of June 30, 2016 , details of the asset retirement obligations (ARO) included in the registrants' Condensed Balance Sheets were as follows: Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Balance at beginning of year $ 3,759 $ 1,448 $ 1,916 $ 130 $ 177 $ 21 Liabilities incurred 9 5 — — — 4 Liabilities settled (66 ) (6 ) (52 ) (1 ) (7 ) — Accretion 77 36 34 1 2 1 Cash flow revisions 699 19 673 3 6 2 Balance at end of period $ 4,478 $ 1,502 $ 2,571 $ 133 $ 178 $ 28 The traditional electric operating companies' increases in cash flow revisions for the six months ended June 30, 2016 primarily relate to changes in ash pond closure strategy. The increase for Georgia Power was due to its decision in June 2016 to cease operating and stop receiving coal ash at all of its ash ponds within the next three years and to eventually close all of its ash ponds either by removal, consolidation, and/or recycling for the beneficial use of coal ash or through closure in place using advanced engineering methods.
Valuation Methodologies	Valuation Methodologies The energy-related derivatives primarily consist of over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflect the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflect the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note (H) for additional information on how these derivatives are used. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. For fair value measurements of the investments within the nuclear decommissioning trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. See Note 1 to the financial statements of Southern Company, Alabama Power, and Georgia Power under "Nuclear Decommissioning" in Item 8 of the Form 10-K for additional information. "Other investments" include investments that are not traded in the open market. The fair value of these investments have been determined based on market factors including comparable multiples and the expectations regarding cash flows and business plan executions.
Earnings per Share	Earnings per Share For Southern Company, the only difference in computing basic and diluted earnings per share is attributable to awards outstanding under the stock option and performance share plans. See Note 8 to the financial statements of Southern Company in Item 8 of the Form 10-K for information on the stock option and performance share plans. The effect of both stock options and performance share award units was determined using the treasury stock method.
Energy-Related Derivatives and Interest Rate Derivatives	Interest Rate Derivatives Southern Company and certain subsidiaries may also enter into interest rate derivatives to hedge exposure to changes in interest rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the effective portion of the derivatives' fair value gains or losses is recorded in OCI and is reclassified into earnings at the same time the hedged transactions affect earnings, with any ineffectiveness recorded directly to earnings. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings, providing an offset, with any difference representing ineffectiveness. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Southern Company, the traditional electric operating companies, and Southern Power are exposed to market risks, primarily commodity price risk and interest rate risk and occasionally foreign currency risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a gross basis. See Note (C) for additional information. In the statements of cash flows, the cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. The cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with classification of the hedged interest or principal, respectively. Energy-Related Derivatives The traditional electric operating companies and Southern Power enter into energy-related derivatives to hedge exposures to electricity, gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies have limited exposure to market volatility in commodity fuel prices and prices of electricity. Each of the traditional electric operating companies manages fuel-hedging programs, implemented per the guidelines of their respective state PSCs, through the use of financial derivative contracts, which is expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in commodity fuel prices and prices of electricity because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted wholesale generating capacity is used to sell electricity. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges — Energy-related derivative contracts which are designated as regulatory hedges relate primarily to the traditional electric operating companies' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through the respective fuel cost recovery clauses. • Cash Flow Hedges — Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in OCI before being recognized in the statements of income in the same period as the hedged transactions are reflected in earnings. • Not Designated — Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric industry. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered.

Introduction (Tables)

Introduction (Tables)	6 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Asset Retirement Obligations	As of June 30, 2016 , details of the asset retirement obligations (ARO) included in the registrants' Condensed Balance Sheets were as follows: Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Balance at beginning of year $ 3,759 $ 1,448 $ 1,916 $ 130 $ 177 $ 21 Liabilities incurred 9 5 — — — 4 Liabilities settled (66 ) (6 ) (52 ) (1 ) (7 ) — Accretion 77 36 34 1 2 1 Cash flow revisions 699 19 673 3 6 2 Balance at end of period $ 4,478 $ 1,502 $ 2,571 $ 133 $ 178 $ 28
Schedule of Goodwill and Other Intangible Assets	Goodwill and other intangible assets consisted of the following: At June 30, 2016 Estimated Useful Life Gross Carrying Amount Accumulated Amortization Intangible Assets, Net (in millions) Intangibles subject to amortization: Southern Company Customer relationships 14-26 years $ 47 $ — $ 47 Trade names 5-9 years 43 — 43 Patents 3-10 years 4 — 4 Backlog 5 years 5 — 5 Southern Power PPA fair value adjustments 20 years 330 (14 ) 316 Total intangibles subject to amortization $ 429 $ (14 ) $ 415 Intangibles not subject to amortization: Southern Company Federal Communications Commission licenses $ 75 $ — $ 75 Goodwill: Southern Company $ 262 $ — $ 262 Southern Power 2 — 2 Total goodwill and other intangible assets $ 768 $ (14 ) $ 754

Contingencies and Regulatory 21

Contingencies and Regulatory Matters (Tables)	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Recovery Balance of Each Regulatory Clause	The balance of each regulatory clause recovery on the balance sheet follows: Regulatory Clause Balance Sheet Location June 30, December 31, 2015 (in millions) Fuel Cost Recovery Other regulatory liabilities, current $ 18 $ 18 Purchased Power Capacity Recovery Under recovered regulatory clause revenues 4 1 Environmental Cost Recovery Under recovered regulatory clause revenues 1 19 Energy Conservation Cost Recovery Other regulatory liabilities, current — 4 The balance of each regulatory clause recovery on the balance sheet follows: Regulatory Clause Balance Sheet Line Item June 30, December 31, 2015 (in millions) Rate CNP Compliance Under recovered regulatory clause revenues $ 7 $ 43 Deferred under recovered regulatory clause revenues 21 — Rate CNP PPA Deferred under recovered regulatory clause revenues 115 99 Retail Energy Cost Recovery Other regulatory liabilities, current 75 238 Deferred over recovered regulatory clause revenues 102 — Natural Disaster Reserve Other regulatory liabilities, deferred 72 75
Current And Actual Cost Estimate for Kemper IGCC	Mississippi Power's Kemper IGCC 2010 project estimate, current cost estimate (which includes the impacts of the Mississippi Supreme Court's (Court) decision discussed herein under "Rate Recovery of Kemper IGCC Costs – 2013 MPSC Rate Order"), and actual costs incurred as of June 30, 2016 , are as follows: Cost Category 2010 Project Estimate (a) Current Cost Estimate (b) Actual Costs (in billions) Plant Subject to Cost Cap (c)(e) $ 2.40 $ 5.43 $ 5.15 Lignite Mine and Equipment 0.21 0.23 0.23 CO 2 Pipeline Facilities 0.14 0.11 0.12 AFUDC (d) 0.17 0.72 0.66 Combined Cycle and Related Assets Placed in (e) — 0.03 0.02 General Exceptions 0.05 0.10 0.09 Deferred Costs (e) — 0.20 0.19 Additional DOE Grants (f) — (0.14 ) (0.14 ) Total Kemper IGCC $ 2.97 $ 6.68 $ 6.32 (a) The 2010 Project Estimate is the certificated cost estimate adjusted to include the certificated estimate for the CO 2 pipeline facilities approved in 2011 by the Mississippi PSC, as well as the lignite mine and equipment, AFUDC, and general exceptions. (b) Amounts in the Current Cost Estimate reflect estimated costs through October 31, 2016. (c) The 2012 MPSC CPCN Order approved a construction cost cap of up to $2.88 billion , net of the Initial DOE Grants and excluding the Cost Cap Exceptions. The Current Cost Estimate and the Actual Costs include non-incremental operating and maintenance costs related to the combined cycle and associated common facilities placed in service in August 2014 that are subject to the $2.88 billion cost cap and exclude post-in-service costs for the lignite mine. See " Rate Recovery of Kemper IGCC Costs – 2013 MPSC Rate Order " herein for additional information. The Current Cost Estimate and the Actual Costs reflect 100% of the costs of the Kemper IGCC. See note (e) for additional information. (d) Mississippi Power's 2010 Project Estimate included recovery of financing costs during construction rather than the accrual of AFUDC. This approach was not approved by the Mississippi PSC as described in " Rate Recovery of Kemper IGCC Costs – 2013 MPSC Rate Order ." The Current Cost Estimate also reflects the impact of a settlement agreement with the wholesale customers for cost-based rates under FERC's jurisdiction. See " FERC Matters " herein for additional information. (e) Non-capital Kemper IGCC-related costs incurred during construction were initially deferred as regulatory assets. Some of these costs are now included in rates and are being recognized through income; however such costs continue to be included in the Current Cost Estimate and the Actual Costs at June 30, 2016. The wholesale portion of debt carrying costs, whether deferred or recognized through income, are not included in the Current Cost Estimate and the Actual Costs at June 30, 2016. See " Rate Recovery of Kemper IGCC Costs – Regulatory Assets and Liabilities " herein for additional information. (f) On April 8, 2016, Mississippi Power received approximately $137 million in additional grants from the DOE for the Kemper IGCC (Additional DOE Grants), which are expected to be used to reduce future rate impacts for customers.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	As of June 30, 2016 , assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using As of June 30, 2016: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives $ — $ 36 $ — $ — $ 36 Interest rate derivatives — 27 — — 27 Nuclear decommissioning trusts (a) 642 917 — 18 1,577 Cash equivalents 1,014 — — — 1,014 Other investments 9 — 1 — 10 Total $ 1,665 $ 980 $ 1 $ 18 $ 2,664 Liabilities: Energy-related derivatives $ — $ 110 $ — $ — $ 110 Interest rate derivatives — 7 — — 7 Foreign currency derivatives — 38 — — 38 Total $ — $ 155 $ — $ — $ 155 Alabama Power Assets: Energy-related derivatives $ — $ 10 $ — $ — $ 10 Nuclear decommissioning trusts (b) Domestic equity 363 67 — — 430 Foreign equity 46 47 — — 93 U.S. Treasury and government agency securities — 24 — — 24 Corporate bonds 21 142 — — 163 Mortgage and asset backed securities — 22 — — 22 Private Equity — — — 18 18 Other — 8 — — 8 Cash equivalents 210 — — — 210 Total $ 640 $ 320 $ — $ 18 $ 978 Liabilities: Energy-related derivatives $ — $ 22 $ — $ — $ 22 Fair Value Measurements Using As of June 30, 2016: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Georgia Power Assets: Energy-related derivatives $ — $ 15 $ — $ — $ 15 Interest rate derivatives — 14 — — 14 Nuclear decommissioning trusts (b) (c) Domestic equity 187 1 — — 188 Foreign equity — 116 — — 116 U.S. Treasury and government agency securities — 109 — — 109 Municipal bonds — 57 — — 57 Corporate bonds — 159 — — 159 Mortgage and asset backed securities — 159 — — 159 Other 25 6 — — 31 Cash equivalents 90 — — — 90 Total $ 302 $ 636 $ — $ — $ 938 Liabilities: Energy-related derivatives $ — $ 5 $ — $ — $ 5 Gulf Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Cash equivalents 20 — — — 20 Total $ 20 $ 2 $ — $ — $ 22 Liabilities: Energy-related derivatives $ — $ 55 $ — $ — $ 55 Interest rate derivatives — 7 — — 7 Total $ — $ 62 $ — $ — $ 62 Mississippi Power Assets: Energy-related derivatives $ — $ 1 $ — $ — $ 1 Cash equivalents 102 — — — 102 Total $ 102 $ 1 $ — $ — $ 103 Liabilities: Energy-related derivatives $ — $ 23 $ — $ — $ 23 Fair Value Measurements Using As of June 30, 2016: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Power Assets: Energy-related derivatives $ — $ 8 $ — $ — $ 8 Cash equivalents 449 — — — 449 Total $ 449 $ 8 $ — $ — $ 457 Liabilities: Energy-related derivatives $ — $ 5 $ — $ — $ 5 Foreign currency derivatives — 38 — — 38 Total $ — $ 43 $ — $ — $ 43 (a) For additional detail, see the nuclear decommissioning trusts sections for Alabama Power and Georgia Power in this table. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. (c) Includes the investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. As of June 30, 2016 , approximately $46 million of the fair market value of Georgia Power's nuclear decommissioning trust funds' securities were on loan to creditors under the funds' managers' securities lending program.
Fair value measurements of investments calculated at net asset value per share as well as the nature and risk of those investments	As of June 30, 2016 , the fair value measurements of private equity investments held in the nuclear decommissioning trust that are calculated at net asset value per share (or its equivalent) as a practical expedient, as well as the nature and risks of those investments, were as follows: As of June 30, 2016: Fair Value Unfunded Commitments Redemption Frequency Redemption Notice Period (in millions) Southern Company $ 18 $ 28 Not Applicable Not Applicable Alabama Power $ 18 $ 28 Not Applicable Not Applicable
Financial instruments for which carrying amount did not equal fair value	As of June 30, 2016 , other financial instruments for which the carrying amount did not equal fair value were as follows: Carrying Amount Fair Value (in millions) Long-term debt, including securities due within one year: Southern Company $ 37,953 $ 40,992 Alabama Power $ 7,090 $ 7,940 Georgia Power $ 10,603 $ 11,881 Gulf Power $ 1,182 $ 1,275 Mississippi Power $ 2,983 $ 2,967 Southern Power $ 4,332 $ 4,523

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Earnings per Share	Shares used to compute diluted earnings per share were as follows: Three Months Ended June 30, 2016 Three Months Ended June 30, 2015 Six Months Ended June 30, 2016 Six Months Ended June 30, 2015 (in millions) As reported shares 934 909 925 910 Effect of options and performance share award units 6 3 6 4 Diluted shares 940 912 931 914
Changes in Stockholders' Equity	The following table presents year-to-date changes in stockholders' equity of Southern Company: Number of Common Shares Common Preferred and Preference Stock of Subsidiaries Total Issued Treasury Noncontrolling Interests (*) (in thousands) (in millions) Balance at December 31, 2015 915,073 (3,352 ) $ 20,592 $ 609 $ 781 $ 21,982 Consolidated net income attributable to Southern Company — — 1,097 — — 1,097 Other comprehensive income (loss) — — (117 ) — — (117 ) Stock issued 27,297 2,599 1,383 — — 1,383 Stock-based compensation — — 82 — — 82 Cash dividends on common stock — — (1,023 ) — — (1,023 ) Contributions from noncontrolling interests — — — — 169 169 Distributions to noncontrolling interests — — — — (10 ) (10 ) Purchase of membership interests from noncontrolling interests — — — — (129 ) (129 ) Net income attributable to noncontrolling interests — — — — 11 11 Other — (19 ) 1 — — 1 Balance at June 30, 2016 942,370 (772 ) $ 22,015 $ 609 $ 822 $ 23,446 Balance at December 31, 2014 908,502 (725 ) $ 19,949 $ 756 $ 221 $ 20,926 Consolidated net income attributable to Southern Company — — 1,138 — — 1,138 Other comprehensive income (loss) — — 7 — — 7 Stock issued 3,222 — 117 — — 117 Stock-based compensation — — 66 — — 66 Stock repurchased, at cost — (2,599 ) (115 ) — — (115 ) Cash dividends on common stock — — (972 ) — — (972 ) Preference stock redemption — — — (150 ) — (150 ) Contributions from noncontrolling interests — — — — 135 135 Distributions to noncontrolling interests — — — — (5 ) (5 ) Net income attributable to noncontrolling interests — — — — 4 4 Other — 25 (8 ) 3 — (5 ) Balance at June 30, 2015 911,724 (3,299 ) $ 20,182 $ 609 $ 355 $ 21,146 (*) Primarily related to Southern Power Company.

Financing (Tables)

Financing (Tables)	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Credit arrangements by company	The following table outlines the committed credit arrangements by company as of June 30, 2016 : Expires Executable Term Loans Due Within One Year Company 2016 2017 2018 2020 Total Unused One Year Two Years Term Out No Term Out (in millions) (in millions) (in millions) (in millions) Southern Company (a) $ — $ — $ 1,000 $ 1,250 $ 2,250 $ 2,250 $ — $ — $ — $ — Alabama Power 3 32 500 800 1,335 1,335 — — — 35 Georgia Power — — — 1,750 1,750 1,732 — — — — Gulf Power 75 40 165 — 280 280 45 — 45 70 Mississippi Power 115 60 — — 175 150 — 15 15 160 Southern Power Company (b) — — — 600 600 560 — — — — Other 25 45 — 40 110 80 20 — 20 50 Total $ 218 $ 177 $ 1,665 $ 4,440 $ 6,500 $ 6,387 $ 65 $ 15 $ 80 $ 315 (a) On May 24, 2016, the $8.1 billion Bridge Agreement to provide Merger financing, to the extent necessary, was terminated. (b) Excluding its subsidiaries. See " Southern Power Project Credit Facilities " below and Note (I) under " Southern Power " for additional information. The table below summarizes each Project Credit Facility as of June 30, 2016 . Project Maturity Date Construction Loan Facility Bridge Loan Facility Loan Facility Total Total Loan Facility Undrawn Letter of Credit Facility Total Letter of Credit Facility Undrawn (in millions) Tranquillity Earlier of PPA COD or December 31, 2016 $ 86 $ 172 $ 258 $ 19 $ 77 $ 26 Roserock Earlier of PPA COD or November 30, 2016 63 180 243 34 23 16 Garland Earlier of PPA COD or November 30, 2016 86 308 394 73 49 23 Total $ 235 $ 660 $ 895 $ 126 $ 149 $ 65
Schedule of Long-term Debt Financing Activities	The following table outlines the long-term debt financing activities for Southern Company and its subsidiaries for the first six months of 2016 : Company Senior Note Issuances Senior Note Maturities and Redemptions Revenue Other Long-Term Debt Issuances Other Long-Term Debt Redemptions and Maturities (a) (in millions) Southern Company $ 8,500 $ — $ — $ — $ — Alabama Power 400 200 — 45 — Georgia Power 650 500 4 300 3 Gulf Power — 125 — — — Mississippi Power — — — 1,100 651 Southern Power 1,241 — — 2 4 Other — — — — 10 Elimination (b) — — — (200 ) (225 ) Total $ 10,791 $ 825 $ 4 $ 1,247 $ 443 (a) Includes reductions in capital lease obligations resulting from cash payments under capital leases. (b) Intercompany loans from Southern Company to Mississippi Power eliminated in Southern Company's Consolidated Financial Statements.

Retirement Benefits (Tables)

Retirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Pension Plans and Postretirement Plans	Components of the net periodic benefit costs for the three and six months ended June 30, 2016 and 2015 were as follows: Pension Plans Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Three Months Ended June 30, 2016 Service cost $ 62 $ 15 $ 18 $ 3 $ 3 Interest cost 101 24 34 4 5 Expected return on plan assets (187 ) (46 ) (65 ) (8 ) (8 ) Amortization: Prior service costs 3 — 2 1 — Net (gain)/loss 37 10 13 1 1 Net cost $ 16 $ 3 $ 2 $ 1 $ 1 Six Months Ended June 30, 2016 Service cost $ 124 $ 29 $ 35 $ 6 $ 6 Interest cost 201 48 68 9 10 Expected return on plan assets (374 ) (92 ) (129 ) (17 ) (17 ) Amortization: Prior service costs 7 1 3 1 — Net (gain)/loss 75 20 27 3 3 Net cost $ 33 $ 6 $ 4 $ 2 $ 2 Three Months Ended June 30, 2015 Service cost $ 64 $ 15 $ 18 $ 3 $ 3 Interest cost 111 27 39 5 6 Expected return on plan assets (181 ) (44 ) (63 ) (8 ) (9 ) Amortization: Prior service costs 7 1 2 — 1 Net (gain)/loss 54 13 19 2 2 Net cost $ 55 $ 12 $ 15 $ 2 $ 3 Six Months Ended June 30, 2015 Service cost $ 128 $ 30 $ 36 $ 6 $ 6 Interest cost 222 53 77 10 11 Expected return on plan assets (362 ) (89 ) (126 ) (16 ) (17 ) Amortization: Prior service costs 13 3 5 — 1 Net (gain)/loss 108 27 38 5 5 Net cost $ 109 $ 24 $ 30 $ 5 $ 6 Postretirement Benefits Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Three Months Ended June 30, 2016 Service cost $ 6 $ 2 $ 1 $ 1 $ 1 Interest cost 17 4 7 — 1 Expected return on plan assets (14 ) (7 ) (5 ) (1 ) (1 ) Amortization: Prior service costs 1 1 1 — — Net (gain)/loss 4 1 2 — — Net cost $ 14 $ 1 $ 6 $ — $ 1 Six Months Ended June 30, 2016 Service cost $ 11 $ 3 $ 3 $ 1 $ 1 Interest cost 35 9 15 1 2 Expected return on plan assets (28 ) (13 ) (11 ) (1 ) (1 ) Amortization: Prior service costs 3 2 1 — — Net (gain)/loss 7 1 4 — — Net cost $ 28 $ 2 $ 12 $ 1 $ 2 Three Months Ended June 30, 2015 Service cost $ 5 $ 2 $ 1 $ — $ 1 Interest cost 20 5 9 1 1 Expected return on plan assets (14 ) (7 ) (6 ) (1 ) (1 ) Amortization: Prior service costs 1 — — — — Net (gain)/loss 4 1 3 — — Net cost $ 16 $ 1 $ 7 $ — $ 1 Six Months Ended June 30, 2015 Service cost $ 11 $ 3 $ 3 $ — $ 1 Interest cost 39 10 17 2 2 Expected return on plan assets (29 ) (13 ) (12 ) (1 ) (1 ) Amortization: Prior service costs 2 1 — — — Net (gain)/loss 9 1 6 — — Net cost $ 32 $ 2 $ 14 $ 1 $ 2

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Change in Unrecognized Tax Benefits	Changes during 2016 for unrecognized tax benefits were as follows: Mississippi Power Southern Power Southern Company (in millions) Unrecognized tax benefits as of December 31, 2015 $ 421 $ 8 $ 433 Tax positions from current periods — 9 10 Balance as of June 30, 2016 $ 421 $ 17 $ 443
Impact on Effective Tax Rate, If Recognized	The impact on the effective tax rate, if recognized, is as follows: As of June 30, 2016 As of December 31, 2015 Mississippi Power Southern Power Southern Company Southern Company (in millions) Tax positions impacting the effective tax rate $ (2 ) $ 17 $ 20 $ 10 Tax positions not impacting the effective tax rate 423 — 423 423 Balance of unrecognized tax benefits $ 421 $ 17 $ 443 $ 433

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of energy-related derivatives	At June 30, 2016 , the net volume of energy-related derivative contracts for natural gas positions for the Southern Company system, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Purchased mmBtu Longest Hedge Date Longest Non-Hedge Date (in millions) Southern Company 250 2020 2016 Alabama Power 60 2019 — Georgia Power 82 2019 — Gulf Power 66 2020 — Mississippi Power 29 2019 — Southern Power 13 2017 2016
Schedule of interest rate derivatives	At June 30, 2016 , the following interest rate derivatives were outstanding: Notional Amount Interest Rate Received Weighted Average Interest Rate Paid Hedge Maturity Date Fair Value (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Gulf Power $ 80 3-month 2.32% December 2026 $ (7 ) Cash Flow Hedges of Existing Debt Southern Company 8 (d) 3-month 1.73% June 2020 — Southern Company 3 (d) 3-month 1.73% June 2020 — Georgia Power 200 3-month 1.01% August 2016 — Fair Value Hedges of Existing Debt Southern Company 250 1.30% 3-month August 2017 2 Southern Company 300 2.75% 3-month June 2020 11 Georgia Power 250 5.40% 3-month June 2018 3 Georgia Power 200 4.25% 3-month December 2019 6 Georgia Power 500 1.95% 3-month December 2018 5 Derivatives not Designated as Hedges Southern Power 65 (a,d) 3-month 2.50% October 2016 (e) — Southern Power 47 (b,d) 3-month 2.21% October 2016 (e) — Southern Power 65 (c,d) 3-month 2.21% November 2016 (f) — Total $ 1,968 $ 20 (a) Swaption at RE Tranquillity LLC. See Note 12 to the financial statements of Southern Company and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information. (b) Swaption at RE Roserock LLC. See Note 12 to the financial statements of Southern Company and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information. (c) Swaption at RE Garland Holdings LLC. See Note 12 to the financial statements of Southern Company and Note 2 to the financial statements of Southern Power in Item 8 of the Form 10-K for additional information. (d) Amortizing notional amount. (e) Represents the mandatory settlement date. Settlement will be based on a 15 -year amortizing swap. (f) Represents the mandatory settlement date. Settlement will be based on a 12 -year amortizing swap.
Schedule of foreign currency derivatives	At June 30, 2016, the following foreign currency derivatives were outstanding: Pay Notional Pay Rate Receive Notional Receive Rate Hedge Fair Value (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 677 2.95% € 600 1.00% June 2022 $ (17 ) Southern Power 564 3.78% 500 1.85% June 2026 (21 ) Total $ 1,241 € 1,100 $ (38 )
Fair value of energy-related derivatives and interest rate derivatives	At June 30, 2016 , the fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: Asset Derivatives at June 30, 2016 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets $ 12 $ 5 $ 6 $ 1 $ — Other deferred charges and assets 16 5 9 1 1 Total derivatives designated as hedging instruments for regulatory purposes $ 28 $ 10 $ 15 $ 2 $ 1 N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets $ 5 $ — $ — $ — $ — $ 5 Other deferred charges and assets 1 — — — — 1 Interest rate derivatives: Other current assets 11 — 6 — — — Other deferred charges and assets 16 — 8 — — — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 33 $ — $ 14 $ — $ — $ 6 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets $ 2 $ — $ — $ — $ — $ 2 Total asset derivatives $ 63 $ 10 $ 29 $ 2 $ 1 $ 8 Liability Derivatives at June 30, 2016 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Liabilities from risk management activities (*) $ 61 $ 17 $ 4 $ 25 $ 15 Other deferred credits and liabilities 44 5 1 30 8 Total derivatives designated as hedging instruments for regulatory purposes $ 105 $ 22 $ 5 $ 55 $ 23 N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Liabilities from risk management activities (*) $ 3 $ — $ — $ — $ — $ 3 Other deferred credits and liabilities 1 — — — — 1 Interest rate derivatives: Liabilities from risk management activities (*) 7 — — 7 — — Foreign currency derivatives: Liabilities from risk management activities (*) 24 — — — — 24 Other deferred credits and liabilities 14 — — — — 14 Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 49 $ — $ — $ 7 $ — $ 42 Derivatives not designated as hedging instruments Energy-related derivatives: Other current liabilities $ 1 $ — $ — $ — $ — $ 1 Total liability derivatives $ 155 $ 22 $ 5 $ 62 $ 23 $ 43 (*) Georgia Power, Mississippi Power, and Southern Power include current liabilities related to derivatives in "Other current liabilities." At December 31, 2015 , the fair value of energy-related derivatives and interest rate derivatives was reflected in the balance sheets as follows: Asset Derivatives at December 31, 2015 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets $ 3 $ 1 $ 2 $ — $ — N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets $ 3 $ — $ — $ — $ — $ 3 Interest rate derivatives: Other current assets 19 — 5 1 — — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 22 $ — $ 5 $ 1 $ — $ 3 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets $ 1 $ — $ — $ — $ — $ 1 Interest rate derivatives: Other current assets 3 — — — — 3 Total derivatives not designated as hedging instruments $ 4 $ — $ — $ — $ — $ 4 Total asset derivatives $ 29 $ 1 $ 7 $ 1 $ — $ 7 Liability Derivatives at December 31, 2015 Fair Value Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Liabilities from risk management activities (*) $ 130 $ 40 $ 12 $ 49 $ 29 Other deferred credits and liabilities 87 15 3 51 18 Total derivatives designated as hedging instruments for regulatory purposes $ 217 $ 55 $ 15 $ 100 $ 47 N/A Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Liabilities from risk management activities (*) $ 2 $ — $ — $ — $ — $ 2 Interest rate derivatives: Liabilities from risk management activities 23 15 — — — — Other deferred credits and liabilities 7 — 6 — — — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 32 $ 15 $ 6 $ — $ — $ 2 Derivatives not designated as hedging instruments Energy-related derivatives: Liabilities from risk management activities (*) $ 1 $ — $ — $ — $ — $ 1 Total liability derivatives $ 250 $ 70 $ 21 $ 100 $ 47 $ 3 (*) Georgia Power, Mississippi Power, and Southern Power include current liabilities related to derivatives in "Other current liabilities."
Offsetting disclosure tables	Amounts related to energy-related derivative contracts, interest rate derivative contracts, and foreign currency derivative contracts at June 30, 2016 and December 31, 2015 are presented in the following tables. Derivative Contracts at June 30, 2016 Fair Value Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Assets Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 36 $ 10 $ 15 $ 2 $ 1 $ 8 Gross amounts not offset in the Balance Sheet (b) (32 ) (8 ) (4 ) (2 ) (1 ) (3 ) Net energy-related derivative assets $ 4 $ 2 $ 11 $ — $ — $ 5 Interest rate and foreign currency derivatives: Interest rate and foreign currency derivatives presented in the Balance Sheet (a) $ 27 $ — $ 14 $ — $ — $ — Gross amounts not offset in the Balance Sheet (b) (18 ) — — — — — Net interest rate and foreign currency derivative assets $ 9 $ — $ 14 $ — $ — $ — Liabilities Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 110 $ 22 $ 5 $ 55 $ 23 $ 5 Gross amounts not offset in the Balance Sheet (b) (32 ) (8 ) (4 ) (2 ) (1 ) (3 ) Net energy-related derivative liabilities $ 78 $ 14 $ 1 $ 53 $ 22 $ 2 Interest rate and foreign currency derivatives: Interest rate and foreign currency derivatives presented in the Balance Sheet (a) $ 45 $ — $ — $ 7 $ — $ 38 Gross amounts not offset in the Balance Sheet (b) (18 ) — — — — — Net interest rate and foreign currency derivative liabilities $ 27 $ — $ — $ 7 $ — $ 38 (a) None of the registrants offsets fair value amounts for multiple derivative instruments executed with the same counterparty on the balance sheets; therefore, gross and net amounts of derivative assets and liabilities presented on the balance sheets are the same. (b) Includes gross amounts subject to netting terms that are not offset on the balance sheets and any cash/financial collateral pledged or received. Derivative Contracts at December 31, 2015 Fair Value Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power Southern Power (in millions) Assets Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 7 $ 1 $ 2 $ — $ — $ 4 Gross amounts not offset in the Balance Sheet (b) (6 ) (1 ) (2 ) — — (1 ) Net energy-related derivative assets $ 1 $ — $ — $ — $ — $ 3 Interest rate derivatives: Interest rate derivatives presented in the Balance Sheet (a) $ 22 $ — $ 5 $ 1 $ — $ 3 Gross amounts not offset in the Balance Sheet (b) (9 ) — (4 ) — — — Net interest rate derivative assets $ 13 $ — $ 1 $ 1 $ — $ 3 Liabilities Energy-related derivatives: Energy-related derivatives presented in the Balance Sheet (a) $ 220 $ 55 $ 15 $ 100 $ 47 $ 3 Gross amounts not offset in the Balance Sheet (b) (6 ) (1 ) (2 ) — — (1 ) Net energy-related derivative liabilities $ 214 $ 54 $ 13 $ 100 $ 47 $ 2 Interest rate derivatives: Interest rate derivatives presented in the Balance Sheet (a) $ 30 $ 15 $ 6 $ — $ — $ — Gross amounts not offset in the Balance Sheet (b) (9 ) — (4 ) — — — Net interest rate derivative liabilities $ 21 $ 15 $ 2 $ — $ — $ — (a) None of the registrants offsets fair value amounts for multiple derivative instruments executed with the same counterparty on the balance sheets; therefore, gross and net amounts of derivative assets and liabilities presented on the balance sheets are the same. (b) Includes gross amounts subject to netting terms that are not offset on the balance sheets and any cash/financial collateral pledged or received.
Pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments	At June 30, 2016 and December 31, 2015 , the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet at June 30, 2016 Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Energy-related derivatives: Other regulatory assets, current $ (61 ) $ (17 ) $ (4 ) $ (25 ) $ (15 ) Other regulatory assets, deferred (44 ) (5 ) (1 ) (30 ) (8 ) Other regulatory liabilities, current (a) 12 5 6 1 — Other regulatory liabilities, deferred (b) 16 5 9 1 1 Total energy-related derivative gains (losses) $ (77 ) $ (12 ) $ 10 $ (53 ) $ (22 ) (a) Georgia Power includes other regulatory liabilities, current in other current liabilities. (b) Georgia Power includes other regulatory liabilities, deferred in other deferred credits and liabilities. Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet at December 31, 2015 Derivative Category and Balance Sheet Location Southern Company Alabama Power Georgia Power Gulf Power Mississippi Power (in millions) Energy-related derivatives: Other regulatory assets, current $ (130 ) $ (40 ) $ (12 ) $ (49 ) $ (29 ) Other regulatory assets, deferred (87 ) (15 ) (3 ) (51 ) (18 ) Other regulatory liabilities, current (*) 3 1 2 — — Total energy-related derivative gains (losses) $ (214 ) $ (54 ) $ (13 ) $ (100 ) $ (47 ) (*) Georgia Power includes other regulatory liabilities, current in other current liabilities.
Pre-tax effects of interest rate derivatives, designated as cash flow hedging instruments	For the three months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives and foreign currency derivatives designated as cash flow hedging instruments were as follows: Derivatives in Cash Flow Hedging Relationships Gain (Loss) Recognized in OCI on Derivative (Effective Portion) Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Statements of Income Location Amount 2016 2015 2016 2015 (in millions) (in millions) Southern Company Interest rate derivatives $ 6 $ 31 Interest expense, net of amounts capitalized $ (4 ) $ (2 ) Foreign currency derivatives (39 ) — Interest expense, net of amounts capitalized (1 ) — Other income (expense), net (20 ) — Total $ (33 ) $ 31 $ (25 ) $ (2 ) Alabama Power Interest rate derivatives $ — $ 7 Interest expense, net of amounts capitalized $ (2 ) $ (1 ) Georgia Power Interest rate derivatives $ — $ 24 Interest expense, net of amounts capitalized $ (1 ) $ (1 ) Gulf Power Interest rate derivatives $ (2 ) $ — Interest expense, net of amounts capitalized $ — $ — Southern Power Foreign currency derivatives $ (39 ) $ — Interest expense, net of amounts capitalized $ (1 ) $ — Other income (expense), net (20 ) — Total $ (39 ) $ — $ (21 ) $ — For the six months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives and foreign currency derivatives designated as cash flow hedging instruments recognized in OCI and those reclassified from accumulated OCI into earnings were as follows: Derivatives in Cash Flow Gain (Loss) Gain (Loss) Reclassified from Accumulated OCI into Statements of Income Location Amount 2016 2015 2016 2015 (in millions) (in millions) Southern Company Interest rate derivatives $ (184 ) $ 2 Interest expense, net of amounts capitalized $ (7 ) $ (4 ) Foreign currency derivatives (39 ) — Interest expense, net of amounts capitalized (1 ) — Other income (expense), net (20 ) — Total $ (223 ) $ 2 $ (28 ) $ (4 ) Alabama Power Interest rate derivatives $ (4 ) $ 1 Interest expense, net of amounts capitalized $ (3 ) $ (1 ) Georgia Power Interest rate derivatives $ — $ 1 Interest expense, net of amounts capitalized $ (2 ) $ (2 ) Gulf Power Interest rate derivatives $ (7 ) $ — Interest expense, net of amounts capitalized $ — $ — Mississippi Power Interest rate derivatives $ — $ — Interest expense, net of amounts capitalized $ (1 ) $ (1 ) Southern Power Interest rate derivatives $ — $ — Interest expense, net of amounts capitalized $ (1 ) $ — Foreign currency derivatives (39 ) — Interest expense, net of amounts capitalized (1 ) — Other income (expense), net (20 ) — Total $ (39 ) $ — $ (22 ) $ —
Pre-tax effects of interest rate derivatives, designated as fair value hedging instruments	For the six months ended June 30, 2016 and 2015 , the pre-tax effects of interest rate derivatives designated as fair value hedging instruments were as follows: Derivatives in Fair Value Hedging Relationships Gain (Loss) Derivative Category Statements of Income Location 2016 2015 (in millions) Southern Company Interest rate derivatives: Interest expense, net of amounts capitalized $ 24 $ 4 Georgia Power Interest rate derivatives: Interest expense, net of amounts capitalized $ 15 $ 2

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Schedule of Business Acquisitions	The preliminary allocation of the purchase price is as follows: PowerSecure Purchase Price June 30, 2016 (in millions) Current assets $ 174 Property, plant, and equipment 48 Goodwill 262 Intangible assets 99 Other assets 8 Current liabilities (111 ) Long-term debt, including current portion (47 ) Deferred credits and other liabilities (4 ) Total purchase price $ 429 The following table presents the preliminary purchase price allocation: Southern Company Gas Purchase Price June 30, 2016 (in millions) Current assets $ 1,474 Property, plant, and equipment 9,795 Goodwill 6,333 Intangible assets 436 Regulatory assets 846 Other assets 273 Current liabilities (2,205 ) Other liabilities (4,529 ) Long-term debt (4,261 ) Noncontrolling interests (160 ) Total purchase price $ 8,002 During 2016 , in accordance with its overall growth strategy, Southern Power acquired or contracted to acquire through its wholly-owned subsidiaries, Southern Renewable Partnerships, LLC or Southern Renewable Energy, Inc., the projects discussed below. Acquisition-related costs were expensed as incurred and were not material. The acquisitions do not include any contingent consideration unless specifically noted. Project Facility Resource Seller; Acquisition Date Approx. Nameplate Capacity Location Southern Power Percentage Ownership Expected/Actual COD PPA Counterparties for Plant Output PPA Contract Period (MW) Acquisitions for the Six Months Ended June 30, 2016 Calipatria Solar Solar Frontier Americas Holding LLC February 11, 2016 20 Imperial County, CA 90 % February 2016 San Diego Gas & Electric Company 20 years East Pecos Solar First Solar, Inc. March 4, 2016 120 Pecos County, TX 100 % Fourth quarter 2016 Austin Energy 15 years Grant Wind Wind Apex Clean Energy Holdings, LLC April 7, 2016 151 Grant County, OK 100 % April 2016 Western Farmers, East Texas, and Northeast Texas Electric Cooperative 20 years Passadumkeag Wind Quantum Utility Generation, LLC June 30, 2016 42 Penobscot County, ME 100 % July 2016 Western Massachusetts Electric Company 15 years Acquisitions Subsequent to June 30, 2016 Henrietta Solar SunPower Corp. July 1, 2016 102 Kings County, CA 51 % (*) July 2016 Pacific Gas and Electric Company 20 years Lamesa Solar RES America Developments Inc. July 1, 2016 102 Dawson County, TX 100 % Second quarter 2017 City of Garland, Texas 15 years Rutherford Solar Cypress Creek Renewables, LLC July 1, 2016 74 Rutherford County, NC 90 % Fourth quarter 2016 Duke Energy Carolinas, LLC 15 years (*) Southern Power owns 100% of the class A membership interests and a wholly-owned subsidiary of the seller owns 100% of the class B membership interests. Southern Power and the class B member are entitled to 51% and 49% , respectively, of all cash distributions from the project. In addition, Southern Power is entitled to substantially all of the federal tax benefits with respect to the transaction.
Schedule of Construction Projects	Through June 30, 2016 , total costs of construction incurred for the projects below were $2.7 billion , of which $1.7 billion remains in CWIP. Including the total construction costs incurred to date and the acquisition prices allocated to CWIP, total aggregate construction costs for the projects below are estimated to be approximately $3.0 billion to $3.2 billion . The ultimate outcome of these matters cannot be determined at this time. Solar Facility Seller Approx. Nameplate Capacity Location Expected/Actual COD PPA Counterparties for Plant Output PPA Contract Period (MW) Butler CERSM, LLC and Community Energy, Inc. 103 Taylor County, GA Fourth quarter 2016 Georgia Power (a) 30 years Desert Stateline (b) First Solar Development, LLC 299 (c) San Bernardino County, CA Through third quarter 2016 Southern California Edison Company (SCE) 20 years Garland and Garland A Recurrent Energy, LLC 205 Kern County, CA Fourth quarter 2016 and SCE 15 years and Roserock Recurrent Energy, LLC 160 Pecos County, TX Fourth quarter 2016 Austin Energy 20 years Sandhills N/A 146 Taylor County, GA Fourth quarter 2016 Cobb, Flint, Irwin, Middle Georgia and Sawnee Electric Membership Corporations 25 years Tranquillity Recurrent Energy, LLC 205 Fresno County, CA July 2016 Shell Energy North America (US), LP/SCE 18 years (a) Butler - Affiliate PPA approved by the FERC. (b) Desert Stateline - On March 29, 2016, Southern Power acquired an additional 15% interest in Desert Stateline. As a result, Southern Power and the class B member are entitled to 66% and 34% , respectively, of all cash distributions from Desert Stateline. In addition, Southern Power will continue to be entitled to substantially all of the federal tax benefits with respect to the transaction. Total estimated construction costs include the acquisition price allocated to CWIP; however, the allocation of the purchase price to individual assets has not been finalized. (c) Desert Stateline - The facility has a total of 299 MWs, of which 110 MWs were placed in service in the fourth quarter 2015 and 152 MWs were placed in service during the six months ended June 30, 2016. Subsequent to June 30, 2016, 37 MWs were placed in service.

Segment and Related Informati29

Segment and Related Information (Tables)	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Financial data for business segments	Financial data for business segments and products and services for the three and six months ended June 30, 2016 and 2015 was as follows: Electric Utilities Traditional Electric Operating Companies Southern Power Eliminations Total All Other Eliminations Consolidated (in millions) Three Months Ended June 30, 2016: Operating revenues $ 4,115 $ 373 $ (109 ) $ 4,379 $ 125 $ (45 ) $ 4,459 Segment net income (loss) (a)(b) 595 89 — 684 (68 ) (4 ) 612 Six Months Ended June 30, 2016: Operating revenues $ 7,884 $ 688 $ (212 ) $ 8,360 $ 172 $ (81 ) $ 8,451 Segment net income (loss) (a)(c) 1,059 139 — 1,198 (94 ) (7 ) 1,097 Total assets at June 30, 2016 $ 70,706 $ 11,082 $ (425 ) $ 81,363 $ 10,505 $ (995 ) $ 90,873 Three Months Ended June 30, 2015: Operating revenues $ 4,077 $ 337 $ (90 ) $ 4,324 $ 43 $ (30 ) $ 4,337 Segment net income (loss) (a)(b) 561 46 — 607 18 4 629 Six Months Ended June 30, 2015: Operating revenues $ 8,025 $ 684 $ (213 ) $ 8,496 $ 83 $ (59 ) $ 8,520 Segment net income (loss) (a)(c) 1,038 79 — 1,117 21 — 1,138 Total assets at December 31, 2015 $ 69,052 $ 8,905 $ (397 ) $ 77,560 $ 1,819 $ (1,061 ) $ 78,318 (a) Attributable to Southern Company. (b) Segment net income (loss) for the traditional electric operating companies includes pre-tax charges for estimated probable losses on the Kemper IGCC of $81 million ( $50 million after tax) and $23 million ( $14 million after tax) for the three months ended June 30, 2016 and 2015 , respectively. See Note (B) under " Integrated Coal Gasification Combined Cycle – Kemper IGCC Schedule and Cost Estimate " for additional information. (c) Segment net income (loss) for the traditional electric operating companies includes pre-tax charges for estimated probable losses on the Kemper IGCC of $134 million ( $83 million after tax) and $32 million ( $20 million after tax) for the six months ended June 30, 2016 and 2015 , respectively. See Note (B) under " Integrated Coal Gasification Combined Cycle – Kemper IGCC Schedule and Cost Estimate " for additional information.
Financial data for products and services	Products and Services Electric Utilities' Revenues Period Retail Wholesale Other Total (in millions) Three Months Ended June 30, 2016 $ 3,748 $ 446 $ 185 $ 4,379 Three Months Ended June 30, 2015 3,714 448 162 4,324 Six Months Ended June 30, 2016 $ 7,124 $ 842 $ 394 $ 8,360 Six Months Ended June 30, 2015 7,256 915 325 8,496

Introduction - Asset Retirement

Introduction - Asset Retirement Obligations (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	$ 3,759
Liabilities incurred	9
Liabilities settled	(66)
Accretion	77
Cash flow revisions	699
Balance at end of period	4,478
Alabama Power [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	1,448
Liabilities incurred	5
Liabilities settled	(6)
Accretion	36
Cash flow revisions	19
Balance at end of period	$ 1,502
Georgia Power [Member]
Property, Plant and Equipment [Line Items]
Asset Retirement Obligation, Period Of Update Cycle	3 years
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	$ 1,916
Liabilities incurred	0
Liabilities settled	(52)
Accretion	34
Cash flow revisions	673
Balance at end of period	2,571
Gulf Power [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	130
Liabilities incurred	0
Liabilities settled	(1)
Accretion	1
Cash flow revisions	3
Balance at end of period	133
Mississippi Power [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	177
Liabilities incurred	0
Liabilities settled	(7)
Accretion	2
Cash flow revisions	6
Balance at end of period	178
Southern Power [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	21
Liabilities incurred	4
Liabilities settled	0
Accretion	1
Cash flow revisions	2
Balance at end of period	$ 28

Introduction - Goodwill and Int

Introduction - Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Indefinite-lived Intangible Assets [Line Items]
Goodwill	$ 264	$ 2
Total goodwill and other intangible assets - gross	768
Total goodwill and other intangible assets - net	754
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - gross carrying amount	429
Intangibles subject to amortization - accumulated amortization	(14)	(12)
Intangibles subject to amortization - net	415
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - accumulated amortization	$ 0
Customer Relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	14 years
Customer Relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	26 years
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - accumulated amortization	$ 0
Trade Names [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	5 years
Trade Names [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	9 years
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - accumulated amortization	$ 0
Patents [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	3 years
Patents [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	10 years
Order or Production Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - accumulated amortization	$ 0
Southern Company [Member]
Indefinite-lived Intangible Assets [Line Items]
Goodwill	262
Southern Company [Member] | Federal Communications Commission Licenses [Member]
Indefinite-lived Intangible Assets [Line Items]
Intangibles not subject to amortization	75
Southern Company [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - gross carrying amount	47
Intangibles subject to amortization - net	47
Southern Company [Member] | Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - gross carrying amount	43
Intangibles subject to amortization - net	43
Southern Company [Member] | Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - gross carrying amount	4
Intangibles subject to amortization - net	$ 4
Southern Company [Member] | Order or Production Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	5 years
Intangibles subject to amortization - gross carrying amount	$ 5
Intangibles subject to amortization - net	5
Southern Power [Member]
Indefinite-lived Intangible Assets [Line Items]
Goodwill	2	2
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - accumulated amortization	$ (14)	$ (12)
Southern Power [Member] | PPA Fair Value Adjustments [Member]
Finite-Lived Intangible Assets [Line Items]
Intangibles subject to amortization - estimated useful life	20 years
Intangibles subject to amortization - gross carrying amount	$ 330
Intangibles subject to amortization - accumulated amortization	(14)
Intangibles subject to amortization - net	$ 316

Introduction - Narrative (Detai

Introduction - Narrative (Details) $ in Millions	30 Months Ended
	Jun. 30, 2016USD ($)agreementlocation	Dec. 31, 2015USD ($)
Related Party Transaction [Line Items]
Intangible Assets, Net (Excluding Goodwill)	$ 490	$ 317
Construction work in progress	9,451	9,082
Southern Power [Member]
Related Party Transaction [Line Items]
Intangible Assets, Net (Excluding Goodwill)	316	317
Construction work in progress	1,852	1,137
Due to Related Parties, Current	$ 80	66
Georgia Power [Member]
Related Party Transaction [Line Items]
Number Of Military Bases For Renewable Generation | location	2
Construction work in progress	$ 4,655	4,775
Due to Related Parties, Current	$ 407	$ 411
Affiliated Entity [Member] | Georgia Power [Member]
Related Party Transaction [Line Items]
Number Of Agreements for Renewable Generation | agreement	2
Construction work in progress	$ 102
Due to Related Parties, Current	$ 13

Contingencies and Regulatory 33

Contingencies and Regulatory Matters - Recovery Balance of Each Regulatory Clause - Alabama Power (Details) - Alabama Power [Member] - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Under recovered regulatory clause revenues, current [Member]
Loss Contingencies [Line Items]
Rate CNP Compliance	$ 7	$ 43
Deferred under recovered regulatory clause revenues [Member]
Loss Contingencies [Line Items]
Rate CNP Compliance	21	0
Rate CNP PPA	115	99
Other regulatory liabilities, current [Member]
Loss Contingencies [Line Items]
Retail Energy Cost Recovery	75	238
Deferred Over Recovered Regulatory Clause Revenues [Member]
Loss Contingencies [Line Items]
Retail Energy Cost Recovery	102	0
Other regulatory liabilities, deferred [Member]
Loss Contingencies [Line Items]
Natural Disaster Reserve	$ 72	$ 75

Contingencies and Regulatory 34

Contingencies and Regulatory Matters - Recovery Balance of Each Regulatory Clause - Gulf Power (Details) - Gulf Power [Member] - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Under recovered regulatory clause revenues [Member]
Loss Contingencies [Line Items]
Purchased Power Capacity Recovery	$ 4	$ 1
Under Recovered Environmental Cost	1	19
Other regulatory liabilities, current [Member]
Loss Contingencies [Line Items]
Fuel Cost Recovery	18	18
Energy Conservation Cost Recovery	$ 0	$ 4

Contingencies and Regulatory 35

Contingencies and Regulatory Matters - Current And Actual Cost Estimate (Details) - Mississippi Power [Member] - USD ($) $ in Millions	Apr. 08, 2016	Jun. 30, 2016	Dec. 31, 2012	Dec. 03, 2015
Loss Contingencies [Line Items]
Cost Related to Grant Funding			$ 245
Kemper IGCC [Member]
Loss Contingencies [Line Items]
Plant Subject to Cost Cap		$ 5,150	$ 2,880
Lignite Mine and Equipment		230
CO2 Pipeline Facilities		120
AFUDC		660
Combined Cycle and Related Assets Placed in Service – Incremental		20
General Exceptions		90
Deferred Costs		190
Total Kemper IGCC, Actual Costs		6,320
Cost Related to Grant Funding		$ (140)
Purchase of Interest		100.00%		15.00%
Government Grants Received	$ 137
Project Estimate [Member] | Kemper IGCC [Member]
Loss Contingencies [Line Items]
Plant Subject to Cost Cap		$ 2,400
Lignite Mine and Equipment		210
CO2 Pipeline Facilities		140
AFUDC		170
Combined Cycle and Related Assets Placed in Service – Incremental		0
General Exceptions		50
Deferred Costs		0
Total Kemper IGCC, Actual Costs		2,970
Cost Related to Grant Funding		0
Current Estimate [Member] | Kemper IGCC [Member]
Loss Contingencies [Line Items]
Plant Subject to Cost Cap		5,430
Lignite Mine and Equipment		230
CO2 Pipeline Facilities		110
AFUDC		720
Combined Cycle and Related Assets Placed in Service – Incremental		30
General Exceptions		100
Deferred Costs		200
Total Kemper IGCC, Actual Costs		6,680
Cost Related to Grant Funding		(140)
Maximum [Member] | Kemper IGCC [Member]
Loss Contingencies [Line Items]
Plant Subject to Cost Cap		$ 2,880

Contingencies and Regulatory 36

Contingencies and Regulatory Matters - Narrative (Details)	Jun. 30, 2016USD ($)mi	Jun. 09, 2016USD ($)	Jun. 03, 2016	May 01, 2016USD ($)	Mar. 31, 2016	Dec. 03, 2015USD ($)	Jul. 07, 2015USD ($)	Jun. 30, 2015USD ($)	Apr. 15, 2015USD ($)	Jan. 01, 2014USD ($)	Mar. 19, 2013	Apr. 30, 2016MW	Dec. 31, 2015USD ($)	Feb. 28, 2013USD ($)	Jan. 31, 2013USD ($)	Jun. 30, 2016USD ($)mi	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)clausemiMW	Dec. 31, 2015USD ($)	Jun. 30, 2015USD ($)	Oct. 31, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2010	Dec. 31, 2009USD ($)	Dec. 31, 2008USD ($)	Jun. 30, 2016USD ($)mi	Dec. 31, 2022	Jun. 30, 2019USD ($)	Jul. 28, 2016MW	May 17, 2016USD ($)	May 03, 2016USD ($)	Apr. 01, 2016USD ($)	Mar. 09, 2016USD ($)	Feb. 01, 2016USD ($)	Jan. 05, 2016USD ($)	Jul. 10, 2015USD ($)
Loss Contingencies [Line Items]
Maximum Borrowing Capacity	$ 6,500,000,000															$ 6,500,000,000		$ 6,500,000,000												$ 6,500,000,000
Construction work in progress	9,451,000,000												$ 9,082,000,000			9,451,000,000		9,451,000,000	$ 9,082,000,000				$ 9,082,000,000							9,451,000,000
Projected Balance Of Regulatory Assets	350,000,000												402,000,000			350,000,000		350,000,000	402,000,000				402,000,000							350,000,000
Kemper IGCC [Member]
Loss Contingencies [Line Items]
Pre-Tax Charge To Income																81,000,000	$ 23,000,000	134,000,000		$ 32,000,000
After Tax Charge To Income																50,000,000	$ 14,000,000	83,000,000		$ 20,000,000
Georgia Power [Member]
Loss Contingencies [Line Items]
Environmental Exit Costs, Assets Previously Disposed, Liability for Remediation	23,000,000															23,000,000		23,000,000												23,000,000
Rate ECR Increase Decrease																																		15.00%
Approved Increase (Decrease) in Annual Billing Based on Fuel Cost Recovery Rate																																		$ (313,000,000)
Additional Construction Capital Costs								$ 3,100,000,000											160,000,000
Percentage of Proportionate Share Owed in Consortium Agreement																													45.70%
Maximum Borrowing Capacity	1,750,000,000															1,750,000,000		$ 1,750,000,000												1,750,000,000
Increase (Decrease) In Projected Certified Construction Capital Costs																		5.00%
Estimated In-service Capital Cost																												$ 4,400,000,000
Amendment To Estimated In-service Capital Cost														$ 4,800,000,000
Delay Of Estimated In-service Date									18 months
Construction work in progress	4,655,000,000												4,775,000,000			4,655,000,000		$ 4,655,000,000	4,775,000,000				4,775,000,000							4,655,000,000
Projected Balance Of Regulatory Assets	123,000,000												123,000,000			123,000,000		123,000,000	123,000,000				123,000,000							123,000,000
Georgia Power [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Additional Construction Capital Costs																													$ 114,000,000
Georgia Power [Member] | Other Current Liabilities [Member]
Loss Contingencies [Line Items]
Over Recovered Fuel Balance	164,000,000															164,000,000		164,000,000												164,000,000
Georgia Power [Member] | Other deferred credits and liabilities [Member]
Loss Contingencies [Line Items]
Over Recovered Fuel Balance													116,000,000						116,000,000				116,000,000
Georgia Power [Member] | Plant Vogtle Units 3 And 4 [Member]
Loss Contingencies [Line Items]
Additional Construction Capital Costs																		141,000,000
Maximum Borrowing Capacity																																					$ 920,000,000
Estimated In-service Capital Cost									$ 5,000,000,000
Monthly Operational Readiness Costs									$ 10,000,000
Construction Financing Costs	1,100,000,000
Construction work in progress	3,700,000,000															3,700,000,000		3,700,000,000												3,700,000,000
Georgia Power [Member] | Plant Vogtle Units 3 And 4 [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Project Settlement Cost To Be Capitalized													350,000,000						350,000,000				350,000,000
Project Settlement Cost To Be Capitalized, Amount Paid To Date	250,000,000															250,000,000		250,000,000												250,000,000
Gulf Power [Member]
Loss Contingencies [Line Items]
Environmental Exit Costs, Assets Previously Disposed, Liability for Remediation	46,000,000															46,000,000		46,000,000												46,000,000
Maximum Borrowing Capacity	280,000,000															280,000,000		280,000,000												280,000,000
Construction work in progress	68,000,000												48,000,000			68,000,000		68,000,000	48,000,000				48,000,000							68,000,000
Reduction In Depreciation Expense																									$ 62,500,000
Reduction In Depreciation Expense Year One																		$ 6,400,000					20,100,000	$ 8,400,000
Number Of Regulatory Clauses | clause																		4
Projected Balance Of Regulatory Assets	65,000,000												90,000,000			65,000,000		$ 65,000,000	90,000,000				90,000,000							65,000,000
Mississippi Power [Member]
Loss Contingencies [Line Items]
Increase in Base Rate Under Cost Based Electric Tariff Due to Settlement				$ 7,000,000
Over Recovered Fuel Cost	76,000,000												71,000,000			76,000,000		76,000,000	71,000,000				71,000,000							76,000,000
Approved Increase (Decrease) in Annual Billing Based on Fuel Cost Recovery Rate																																						$ (36,000,000)	$ (120,000,000)
Maximum Borrowing Capacity	175,000,000															175,000,000		175,000,000												175,000,000
Construction work in progress	2,429,000,000												2,254,000,000			2,429,000,000		$ 2,429,000,000	2,254,000,000				2,254,000,000							2,429,000,000
PSC Retail Rate Increase (Decrease)																																			$ (2,000,000)
Annual PEP Filing Rate Increase Amount																																				$ 5,000,000
Plant Capacity Under Coal Gasification Combined Cycle Technology (in MWs) | MW																		582
Costs associated with CCP12 grant funds																										$ 245,000,000
Increase Retail Rates In Year One											15.00%
Increase Retail Rates In Year Two										3.00%
Settlement Agreement Collection Amount To Mitigate Rate Impact Year Two										$ 156,000,000
Retail Rate Recovery							$ 342,000,000
Carrying Costs Associated With Retail Rate Recovery							$ 29,000,000
Projected Balance Of Regulatory Assets	97,000,000												95,000,000			97,000,000		$ 97,000,000	95,000,000				95,000,000							97,000,000
Regulatory Liabilities	5,000,000															5,000,000		5,000,000												5,000,000
Mississippi Power [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Costs Due To Extension Of In-service Date																		25,000,000
Mississippi Power [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Costs Due To Extension Of In-service Date																		35,000,000
Mississippi Power [Member] | Construction in Progress [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	2,550,000,000															2,550,000,000		2,550,000,000												2,550,000,000
Mississippi Power [Member] | MRA Revenue [Member]
Loss Contingencies [Line Items]
Over Recovered Fuel Cost	$ 23,000,000												24,000,000			$ 23,000,000		$ 23,000,000	24,000,000				24,000,000							$ 23,000,000
Mississippi Power [Member] | Electricity Generation Plant, Non-Nuclear [Member]
Loss Contingencies [Line Items]
Estimated Cost															$ 2,400,000,000											2,400,000,000
Alternate Financing																									$ 1,000,000,000
Mississippi Power [Member] | Kemper IGCC [Member]
Loss Contingencies [Line Items]
Period of Amortization of Regulatory Assets					36 months
Co Two Pipeline Infrastructure (in miles) | mi	61															61		61												61
Estimated Cost																		$ 5,150,000,000								$ 2,880,000,000
Costs associated with CCP12 grant funds																		$ (140,000,000)
Period of Extension for In-service Date																		1 month
Pre-Tax Charge To Income																$ 81,000,000		$ 134,000,000												$ 2,550,000,000
After Tax Charge To Income																$ 50,000,000		83,000,000												$ 1,570,000,000
Monthly Charge Of Allowance For Equity Funds Used During Construction																		14,000,000
Monthly Cost Regulatory Assets Deferred																		$ 3,000,000
Purchase of Interest	100.00%					15.00%										100.00%		100.00%												100.00%
Maximum Cap Construction Cost																		$ 6,320,000,000
Regulatory Assets	$ 114,000,000															$ 114,000,000		114,000,000												$ 114,000,000
Projected Balance Of Regulatory Assets	101,000,000															101,000,000		101,000,000												101,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Current Estimate [Member]
Loss Contingencies [Line Items]
Estimated Cost																		5,430,000,000
Costs associated with CCP12 grant funds																		(140,000,000)
Maximum Cap Construction Cost																		$ 6,680,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | In-Service Asset Proposal [Member]
Loss Contingencies [Line Items]
PSC Retail Rate Increase (Decrease)						$ 126,000,000																																		$ 159,000,000
Public Utilities, Approved Equity Capital Structure, Percentage						49.733%
Public Utilities, Approved Return on Equity, Percentage						9.225%
Customer Refund													11,000,000
Period to File Subsequent Rate Request						18 months
Mississippi Power [Member] | Kemper IGCC [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value		$ 100,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Amortization Period of Regulatory Assets and Liabilities																		2 years
Mississippi Power [Member] | Kemper IGCC [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Estimated Cost																		$ 2,880,000,000
Amortization Period of Regulatory Assets and Liabilities																		10 years
Mississippi Power [Member] | Kemper IGCC [Member] | Property, Plant and Equipment [Member]
Loss Contingencies [Line Items]
Estimated Cost																		$ 3,590,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Other Property And Investments [Member]
Loss Contingencies [Line Items]
Estimated Cost																		6,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Fossil Fuel Stock [Member]
Loss Contingencies [Line Items]
Estimated Cost																		81,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Materials And Supplies [Member]
Loss Contingencies [Line Items]
Estimated Cost																		46,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Other regulatory assets deferred [Member]
Loss Contingencies [Line Items]
Estimated Cost																		35,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Other regulatory assets, deferred [Member]
Loss Contingencies [Line Items]
Estimated Cost																		180,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Other current assets [Member]
Loss Contingencies [Line Items]
Estimated Cost																		1,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Other deferred charges and assets [Member]
Loss Contingencies [Line Items]
Estimated Cost																		11,000,000
Mississippi Power [Member] | Kemper IGCC [Member] | Current Assets [Member]
Loss Contingencies [Line Items]
Regulatory Assets	35,000,000															35,000,000		35,000,000												35,000,000
Mississippi Power [Member] | Mine [Member]
Loss Contingencies [Line Items]
Term of Management Fee Contract																											40 years
Alabama Power [Member]
Loss Contingencies [Line Items]
Maximum Borrowing Capacity	1,335,000,000															1,335,000,000		1,335,000,000												1,335,000,000
Construction work in progress	423,000,000												801,000,000			423,000,000		423,000,000	801,000,000				801,000,000							423,000,000
Projected Balance Of Regulatory Assets	$ 87,000,000												$ 115,000,000			$ 87,000,000		$ 87,000,000	$ 115,000,000				$ 115,000,000							$ 87,000,000
Alabama Power [Member] | Plant Greene County Units 1 And 2 [Member]
Loss Contingencies [Line Items]
Capacity Of Units Included In Request For Decertification Of Units | MW												300
Scenario, Forecast [Member] | Georgia Power [Member]
Loss Contingencies [Line Items]
Cost Recovery, New Nuclear																																$ 99,000,000
Additional Construction Capital Costs																						$ 5,440,000,000
Scenario, Forecast [Member] | Georgia Power [Member] | Plant Vogtle Units 3 And 4 [Member]
Loss Contingencies [Line Items]
Construction Financing Costs																						$ 2,400,000,000
Scenario, Forecast [Member] | Mississippi Power [Member]
Loss Contingencies [Line Items]
AFUDC Cost																					$ 8,000,000
Scenario, Forecast [Member] | Georgia Power And Atlanta Gas Light Company [Member]
Loss Contingencies [Line Items]
Percentage Basis, Net Merger Savings																															40.00%
Customers [Member] | Scenario, Forecast [Member]
Loss Contingencies [Line Items]
Percentage Basis, Net Merger Savings																															60.00%
Subsequent Event [Member] | Georgia Power [Member]
Loss Contingencies [Line Items]
Capacity of Renewable Resources Approved For Procurement | MW																																	1,200
Capacity of Renewable Resources Approved For Self-build | MW																																	200
Subsequent Event [Member] | Georgia Power [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Capacity of Renewable Resources Considered For Renewable Commercial and Industrial Program | MW																																	200
Subsequent Event [Member] | Georgia Power [Member] | Plant Mitchell Units 3, 4A, and 4B [Member]
Loss Contingencies [Line Items]
Capacity Of Units Approved For Decertification Of Units | MW																																	217
Subsequent Event [Member] | Georgia Power [Member] | Plant Kraft Unit 1 [Member]
Loss Contingencies [Line Items]
Capacity Of Units Approved For Decertification Of Units | MW																																	17
Intercession City Combustion Turbine [Member] | Subsequent Event [Member] | Georgia Power [Member]
Loss Contingencies [Line Items]
Capacity Of Units Approved For Decertification Of Units | MW																																	143
Jointly Owned Utility Plant, Proportionate Ownership Share																																	33.00%
Denbury Onshore, Contractor [Member] | Mississippi Power [Member] | Electricity Generation Plant, Non-Nuclear [Member]
Loss Contingencies [Line Items]
Long-term Contract For Purchase of Carbon Dioxide, Term			16 years
Treetop Midstream Services, LLC, Contractor [Member] | Mississippi Power [Member] | Kemper IGCC [Member]
Loss Contingencies [Line Items]
Long Term Contract For Purchase Of Percentage of Carbon Dioxide Captured from Plant	30.00%															30.00%		30.00%												30.00%
Denbury Onshore, Contractor [Member] | Mississippi Power [Member] | Kemper IGCC [Member]
Loss Contingencies [Line Items]
Long Term Contract For Purchase Of Percentage of Carbon Dioxide Captured from Plant	70.00%		100.00%													70.00%		70.00%												70.00%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Assets:
Fair Value	$ 18
Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	36
Interest rate derivatives	27
Nuclear decommissioning trusts	1,577
Cash equivalents	1,014
Other investments	10
Total	2,664
Liabilities:
Energy-related derivatives	110
Interest rate derivatives	7
Foreign Currency Fair Value Hedge Liability at Fair Value	38
Total	155
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Energy-related derivatives	0
Interest rate derivatives	0
Nuclear decommissioning trusts	642
Cash equivalents	1,014
Other investments	9
Total	1,665
Liabilities:
Energy-related derivatives	0
Interest rate derivatives	0
Foreign Currency Fair Value Hedge Liability at Fair Value	0
Total	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Energy-related derivatives	36
Interest rate derivatives	27
Nuclear decommissioning trusts	917
Cash equivalents	0
Other investments	0
Total	980
Liabilities:
Energy-related derivatives	110
Interest rate derivatives	7
Foreign Currency Fair Value Hedge Liability at Fair Value	38
Total	155
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Energy-related derivatives	0
Interest rate derivatives	0
Nuclear decommissioning trusts	0
Cash equivalents	0
Other investments	1
Total	1
Liabilities:
Energy-related derivatives	0
Interest rate derivatives	0
Foreign Currency Fair Value Hedge Liability at Fair Value	0
Total	0
Alabama Power [Member]
Assets:
Energy-related derivatives	10	$ 1
Fair Value	18
Liabilities:
Energy-related derivatives	22	70
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	10
Cash equivalents	210
Total	978
Liabilities:
Energy-related derivatives	22
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	430
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	93
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	24
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	163
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	22
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Private Equity Funds [Member]
Assets:
Nuclear decommissioning trusts	18
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	8
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	210
Total	640
Liabilities:
Energy-related derivatives	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	363
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	46
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	21
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Private Equity Funds [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Energy-related derivatives	10
Cash equivalents	0
Total	320
Liabilities:
Energy-related derivatives	22
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	67
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	47
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	24
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	142
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	22
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Private Equity Funds [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	8
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	0
Total	0
Liabilities:
Energy-related derivatives	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Private Equity Funds [Member]
Assets:
Nuclear decommissioning trusts	0
Alabama Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member]
Assets:
Energy-related derivatives	29	7
Nuclear decommissioning trusts	46
Liabilities:
Energy-related derivatives	5	21
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	15
Interest rate derivatives	14
Cash equivalents	90
Total	938
Liabilities:
Energy-related derivatives	5
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	188
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	116
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	109
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Municipal bonds [Member]
Assets:
Nuclear decommissioning trusts	57
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	159
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	159
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	31
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Energy-related derivatives	0
Interest rate derivatives	0
Cash equivalents	90
Total	302
Liabilities:
Energy-related derivatives	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	187
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Municipal bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	25
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Energy-related derivatives	15
Interest rate derivatives	14
Cash equivalents	0
Total	636
Liabilities:
Energy-related derivatives	5
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	1
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	116
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	109
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Municipal bonds [Member]
Assets:
Nuclear decommissioning trusts	57
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	159
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	159
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	6
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Energy-related derivatives	0
Interest rate derivatives	0
Cash equivalents	0
Total	0
Liabilities:
Energy-related derivatives	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Domestic Equity [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign equity [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury and government agency securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Municipal bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate bonds [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage and asset backed securities [Member]
Assets:
Nuclear decommissioning trusts	0
Georgia Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other investments [Member]
Assets:
Nuclear decommissioning trusts	0
Gulf Power [Member]
Assets:
Energy-related derivatives	2	1
Liabilities:
Energy-related derivatives	62	100
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	2
Cash equivalents	20
Total	22
Liabilities:
Energy-related derivatives	55
Interest rate derivatives	7
Total	62
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	20
Total	20
Liabilities:
Energy-related derivatives	0
Interest rate derivatives	0
Total	0
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Energy-related derivatives	2
Cash equivalents	0
Total	2
Liabilities:
Energy-related derivatives	55
Interest rate derivatives	7
Total	62
Gulf Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	0
Total	0
Liabilities:
Energy-related derivatives	0
Interest rate derivatives	0
Total	0
Mississippi Power [Member]
Assets:
Energy-related derivatives	1	0
Liabilities:
Energy-related derivatives	23	47
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	1
Cash equivalents	102
Total	103
Liabilities:
Energy-related derivatives	23
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	102
Total	102
Liabilities:
Energy-related derivatives	0
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Energy-related derivatives	1
Cash equivalents	0
Total	1
Liabilities:
Energy-related derivatives	23
Mississippi Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	0
Total	0
Liabilities:
Energy-related derivatives	0
Southern Power [Member]
Assets:
Energy-related derivatives	8	7
Liabilities:
Energy-related derivatives	43	$ 3
Southern Power [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Energy-related derivatives	8
Cash equivalents	449
Total	457
Liabilities:
Energy-related derivatives	5
Foreign Currency Fair Value Hedge Liability at Fair Value	38
Total	43
Southern Power [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	449
Total	449
Liabilities:
Energy-related derivatives	0
Foreign Currency Fair Value Hedge Liability at Fair Value	0
Total	0
Southern Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Energy-related derivatives	8
Cash equivalents	0
Total	8
Liabilities:
Energy-related derivatives	5
Foreign Currency Fair Value Hedge Liability at Fair Value	38
Total	43
Southern Power [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Energy-related derivatives	0
Cash equivalents	0
Total	0
Liabilities:
Energy-related derivatives	0
Foreign Currency Fair Value Hedge Liability at Fair Value	0
Total	0
Nuclear Decommissioning Trusts [Member]
Assets:
Fair Value	18
Nuclear Decommissioning Trusts [Member] | Alabama Power [Member]
Assets:
Fair Value	$ 18

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurements Of Investments Calculated At Net Asset Value Per Share (Details) $ in Millions	Jun. 30, 2016USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 18
Private Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	18
Unfunded Commitments	28
Alabama Power [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	18
Alabama Power [Member] | Private Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	18
Unfunded Commitments	$ 28

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments for which Carrying Amount did not Equal Fair Value (Details) $ in Millions	Jun. 30, 2016USD ($)
Southern Company [Member]
Long-term debt:
Long-term debt, including securities due within one year, Carrying Amount	$ 37,953
Long-term debt, including securities due within one year, Fair Value	40,992
Alabama Power [Member]
Long-term debt:
Long-term debt, including securities due within one year, Carrying Amount	7,090
Long-term debt, including securities due within one year, Fair Value	7,940
Georgia Power [Member]
Long-term debt:
Long-term debt, including securities due within one year, Carrying Amount	10,603
Long-term debt, including securities due within one year, Fair Value	11,881
Gulf Power [Member]
Long-term debt:
Long-term debt, including securities due within one year, Carrying Amount	1,182
Long-term debt, including securities due within one year, Fair Value	1,275
Mississippi Power [Member]
Long-term debt:
Long-term debt, including securities due within one year, Carrying Amount	2,983
Long-term debt, including securities due within one year, Fair Value	2,967
Southern Power [Member]
Long-term debt:
Long-term debt, including securities due within one year, Carrying Amount	4,332
Long-term debt, including securities due within one year, Fair Value	$ 4,523

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 28	$ (1)	$ 48	$ 31
Private Equity Funds [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Liquidations term			10 years
Alabama Power [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	29	5	$ 40	19
Georgia Power [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ (1)	$ (6)	$ 8	$ 12

Stockholders' Equity - Earnings

Stockholders' Equity - Earnings per Share (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Equity [Abstract]
As reported shares	934	909	925	910
Effect of options and performance share award units	6	3	6	4
Diluted shares	940	912	931	914
Stock options and performance share award units that were not included in the diluted earnings per share calculation (in shares)	0	15	0	1

Stockholders' Equity - Changes

Stockholders' Equity - Changes in Stockholders' Equity (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Changes in Stockholders' Equity
Beginning Balance, Treasury Shares			(3,400)
Beginning Balance			$ 21,982	$ 20,926
Consolidated net income attributable to Southern Company	$ 612	$ 629	1,097	1,138
Other comprehensive income (loss)	$ (3)	22	(117)	7
Stock issued			1,383	117
Stock-based compensation			82	66
Stock repurchased, at cost				(115)
Cash dividends on common stock			(1,023)	(972)
Preference stock redemption				(150)
Contributions from noncontrolling interests			169	135
Distributions to noncontrolling interests			(10)	(5)
Purchase of membership interests from noncontrolling interests			(129)
Net income attributable to noncontrolling interests			11	4
Other			$ 1	(5)
Beginning Balance, Treasury Shares	(800)		(800)
Ending Balance	$ 23,446	$ 21,146	$ 23,446	$ 21,146
Noncontrolling Interest in Preferred Unit Holders	609		609		$ 609
Nonredeemable Noncontrolling Interest	$ 822		$ 822		$ 781
Number of Common shares Issued [Member]
Changes in Stockholders' Equity
Beginning Balance, Shares			915,073	908,502
Stock issued, Shares			27,297	3,222
Ending Balance, Shares	942,370	911,724	942,370	911,724
Number of Common shares Treasury [Member]
Changes in Stockholders' Equity
Beginning Balance, Treasury Shares			(3,352)	(725)
Stock issued, Shares			2,599
Stock repurchased, at cost, Shares				(2,599)
Other, Shares			(19)	25
Beginning Balance, Treasury Shares	(772)	(3,299)	(772)	(3,299)
Common Stockholders' Equity [Member]
Changes in Stockholders' Equity
Beginning Balance			$ 20,592	$ 19,949
Consolidated net income attributable to Southern Company			1,097	1,138
Other comprehensive income (loss)			(117)	7
Stock issued			1,383	117
Stock-based compensation			82	66
Stock repurchased, at cost				(115)
Cash dividends on common stock			(1,023)	(972)
Other			1	(8)
Ending Balance	$ 22,015	$ 20,182	22,015	20,182
Preferred And Preference Stock [Member]
Changes in Stockholders' Equity
Beginning Balance			609	756
Preference stock redemption				(150)
Other				3
Ending Balance	609	609	609	609
Noncontrolling Interest [Member]
Changes in Stockholders' Equity
Beginning Balance			781	221
Contributions from noncontrolling interests			169	135
Distributions to noncontrolling interests			(10)	(5)
Purchase of membership interests from noncontrolling interests			(129)
Net income attributable to noncontrolling interests			11	4
Ending Balance	$ 822	$ 355	$ 822	$ 355

Financing - Schedule of Credit

Financing - Schedule of Credit Arrangements (Details) - USD ($)	Jun. 30, 2016	May 24, 2016
Line of Credit Facility [Line Items]
Expires, 2016	$ 218,000,000
Expires, 2017	177,000,000
Expires, 2018	1,665,000,000
Expires, 2020	4,440,000,000
Total	6,500,000,000
Unused	6,387,000,000
Executable Term Loans, One Year	65,000,000
Executable Term Loans, Two Years	15,000,000
Due Within One Year, Term Out	80,000,000
Due Within One Year, No Term Out	315,000,000
Bridge Agreement [Member]
Line of Credit Facility [Line Items]
Total		$ 8,100,000,000
Southern Company [Member]
Line of Credit Facility [Line Items]
Expires, 2016	0
Expires, 2017	0
Expires, 2018	1,000,000,000
Expires, 2020	1,250,000,000
Total	2,250,000,000
Unused	2,250,000,000
Executable Term Loans, One Year	0
Executable Term Loans, Two Years	0
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	0
Alabama Power [Member]
Line of Credit Facility [Line Items]
Expires, 2016	3,000,000
Expires, 2017	32,000,000
Expires, 2018	500,000,000
Expires, 2020	800,000,000
Total	1,335,000,000
Unused	1,335,000,000
Executable Term Loans, One Year	0
Executable Term Loans, Two Years	0
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	35,000,000
Georgia Power [Member]
Line of Credit Facility [Line Items]
Expires, 2016	0
Expires, 2017	0
Expires, 2018	0
Expires, 2020	1,750,000,000
Total	1,750,000,000
Unused	1,732,000,000
Executable Term Loans, One Year	0
Executable Term Loans, Two Years	0
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	0
Gulf Power [Member]
Line of Credit Facility [Line Items]
Expires, 2016	75,000,000
Expires, 2017	40,000,000
Expires, 2018	165,000,000
Expires, 2020	0
Total	280,000,000
Unused	280,000,000
Executable Term Loans, One Year	45,000,000
Executable Term Loans, Two Years	0
Due Within One Year, Term Out	45,000,000
Due Within One Year, No Term Out	70,000,000
Mississippi Power [Member]
Line of Credit Facility [Line Items]
Expires, 2016	115,000,000
Expires, 2017	60,000,000
Expires, 2018	0
Expires, 2020	0
Total	175,000,000
Unused	150,000,000
Executable Term Loans, One Year	0
Executable Term Loans, Two Years	15,000,000
Due Within One Year, Term Out	15,000,000
Due Within One Year, No Term Out	160,000,000
Southern Power [Member]
Line of Credit Facility [Line Items]
Expires, 2016	0
Expires, 2017	0
Expires, 2018	0
Expires, 2020	600,000,000
Total	600,000,000
Unused	560,000,000
Executable Term Loans, One Year	0
Executable Term Loans, Two Years	0
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	0
Other [Member]
Line of Credit Facility [Line Items]
Expires, 2016	25,000,000
Expires, 2017	45,000,000
Expires, 2018	0
Expires, 2020	40,000,000
Total	110,000,000
Unused	80,000,000
Executable Term Loans, One Year	20,000,000
Executable Term Loans, Two Years	0
Due Within One Year, Term Out	20,000,000
Due Within One Year, No Term Out	$ 50,000,000

Financing - Schedule of Line of

Financing - Schedule of Line of Credit Facilities (Details)	Jun. 30, 2016USD ($)
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	$ 6,500,000,000
Remaining Borrowing Capacity	6,387,000,000
Southern Power [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	600,000,000
Remaining Borrowing Capacity	560,000,000
Construction Loans [Member] | Southern Power [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	235,000,000
Construction Loans [Member] | Southern Power [Member] | RE Tranquility Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	86,000,000
Construction Loans [Member] | Southern Power [Member] | RE Roserock Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	63,000,000
Construction Loans [Member] | Southern Power [Member] | RE Garland Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	86,000,000
Bridge Loan [Member] | Southern Power [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	660,000,000
Bridge Loan [Member] | Southern Power [Member] | RE Tranquility Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	172,000,000
Bridge Loan [Member] | Southern Power [Member] | RE Roserock Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	180,000,000
Bridge Loan [Member] | Southern Power [Member] | RE Garland Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	308,000,000
Construction Loan And Bridge Loan [Member] | Southern Power [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	895,000,000
Remaining Borrowing Capacity	126,000,000
Construction Loan And Bridge Loan [Member] | Southern Power [Member] | RE Tranquility Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	258,000,000
Remaining Borrowing Capacity	19,000,000
Construction Loan And Bridge Loan [Member] | Southern Power [Member] | RE Roserock Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	243,000,000
Remaining Borrowing Capacity	34,000,000
Construction Loan And Bridge Loan [Member] | Southern Power [Member] | RE Garland Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	394,000,000
Remaining Borrowing Capacity	73,000,000
Letter of Credit [Member] | Southern Power [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	149,000,000
Remaining Borrowing Capacity	65,000,000
Letter of Credit [Member] | Southern Power [Member] | RE Tranquility Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	77,000,000
Remaining Borrowing Capacity	26,000,000
Letter of Credit [Member] | Southern Power [Member] | RE Roserock Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	23,000,000
Remaining Borrowing Capacity	16,000,000
Letter of Credit [Member] | Southern Power [Member] | RE Garland Holdings, LLC [Member]
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity	49,000,000
Remaining Borrowing Capacity	$ 23,000,000

Financing - Schedule of Long-Te

Financing - Schedule of Long-Term Debt Financing Activities (Details) - USD ($)	1 Months Ended	6 Months Ended
	May 31, 2016	Jun. 30, 2016
Debt Instrument [Line Items]
Senior Note Issuances		$ 10,791,000,000
Senior Note Maturities and Redemptions		825,000,000
Revenue Bond Maturities Redemptions and Repurchases		4,000,000
Other Long-Term Debt Issuances		1,247,000,000
Other Long-Term Debt Redemptions and Maturities		443,000,000
Consolidation, Eliminations [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		(200,000,000)
Other Long-Term Debt Redemptions and Maturities		(225,000,000)
Southern Company [Member]
Debt Instrument [Line Items]
Senior Note Issuances	$ 8,500,000,000	8,500,000,000
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		0
Other Long-Term Debt Redemptions and Maturities		0
Alabama Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		400,000,000
Senior Note Maturities and Redemptions		200,000,000
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		45,000,000
Other Long-Term Debt Redemptions and Maturities		0
Georgia Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		650,000,000
Senior Note Maturities and Redemptions		500,000,000
Revenue Bond Maturities Redemptions and Repurchases		4,000,000
Other Long-Term Debt Issuances		300,000,000
Other Long-Term Debt Redemptions and Maturities		3,000,000
Gulf Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		125,000,000
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		0
Other Long-Term Debt Redemptions and Maturities		0
Mississippi Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		1,100,000,000
Other Long-Term Debt Redemptions and Maturities		651,000,000
Southern Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances		1,241,000,000
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		2,000,000
Other Long-Term Debt Redemptions and Maturities		4,000,000
Other [Member]
Debt Instrument [Line Items]
Senior Note Issuances		0
Senior Note Maturities and Redemptions		0
Revenue Bond Maturities Redemptions and Repurchases		0
Other Long-Term Debt Issuances		0
Other Long-Term Debt Redemptions and Maturities		$ 10,000,000

Financing - Narrative (Details)

Financing - Narrative (Details)	Jun. 27, 2016USD ($)	Mar. 08, 2016USD ($)	May 31, 2016USD ($)	Mar. 31, 2016USD ($)	Jan. 31, 2016USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016EUR (€)	Mar. 14, 2016USD ($)	Jan. 29, 2016USD ($)	Jan. 19, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding						$ 1,900,000,000	$ 1,900,000,000
Maximum Borrowing Capacity						6,500,000,000	6,500,000,000
Senior Note Issuances							10,791,000,000
Remaining Borrowing Capacity						6,387,000,000	6,387,000,000
Alabama Power [Member]
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding						890,000,000	890,000,000
Fixed rate pollution control revenue bonds outstanding						87,000,000	87,000,000
Maximum Borrowing Capacity						1,335,000,000	1,335,000,000
Senior Note Issuances							400,000,000
Repayments of Senior Debt							200,000,000	$ 250,000,000
Capital contributions from parent company							237,000,000	10,000,000
Remaining Borrowing Capacity						1,335,000,000	1,335,000,000
Alabama Power [Member] | Series FF [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					5.20%
Alabama Power [Member] | Senior Notes [Member] | Series 2016A [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount					$ 400,000,000
Debt Instrument, Interest Rate, Stated Percentage					4.30%
Alabama Power [Member] | Unsecured Debt [Member] | Series FF [Member]
Debt Instrument [Line Items]
Repayments of Senior Debt					$ 200,000,000
Alabama Power [Member] | Bank Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 45,000,000
Debt Instrument, Interest Rate, Stated Percentage				2.38%
Georgia Power [Member]
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding						868,000,000	868,000,000
Fixed rate pollution control revenue bonds outstanding						212,000,000	212,000,000
Line of Credit Facility, Current Borrowing Capacity						300,000,000	300,000,000
Maximum Borrowing Capacity						1,750,000,000	1,750,000,000
Senior Note Issuances							650,000,000
Repayments of Senior Debt							500,000,000	125,000,000
Capital contributions from parent company							239,000,000	23,000,000
Remaining Borrowing Capacity						$ 1,732,000,000	$ 1,732,000,000
Georgia Power [Member] | Senior Notes [Member] | Series 2016A [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 325,000,000
Debt Instrument, Interest Rate, Stated Percentage				3.25%
Georgia Power [Member] | Senior Notes [Member] | Series 2016B [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 325,000,000
Debt Instrument, Interest Rate, Stated Percentage				2.40%
Georgia Power [Member] | Unsecured Debt [Member] | Series 2013B [Member]
Debt Instrument [Line Items]
Repayments of Senior Debt				$ 250,000,000
Georgia Power [Member] | Line of Credit [Member] | FFB Credit Facility due 2044 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage						2.571%	2.571%		2.571%
Gulf Power [Member]
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding						$ 82,000,000	$ 82,000,000
Fixed rate pollution control revenue bonds outstanding						21,000,000	21,000,000
Maximum Borrowing Capacity						280,000,000	280,000,000
Senior Note Issuances							0
Repayments of Senior Debt							125,000,000	0
Remaining Borrowing Capacity						280,000,000	280,000,000
Gulf Power [Member] | Series 2011A [Member]
Debt Instrument [Line Items]
Redemption Amount Of Principal Notes			$ 125,000,000
Gulf Power [Member] | Senior Notes [Member] | Series 2011A [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			5.75%
Gulf Power [Member] | Bank Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 100,000,000
Debt instrument term			11 months
Mississippi Power [Member]
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding						40,000,000	40,000,000
Line of Credit Facility, Current Borrowing Capacity						100,000,000	100,000,000			$ 50,000,000	$ 50,000,000	$ 100,000,000
Maximum Borrowing Capacity						175,000,000	175,000,000
Senior Note Issuances							0
Promissory Note					$ 275,000,000		0	301,000,000
Capital contributions from parent company	$ 225,000,000						226,000,000	77,000,000
Long-term Debt, Affiliated						551,000,000	551,000,000						$ 576,000,000
Remaining Borrowing Capacity						150,000,000	150,000,000
Mississippi Power [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Redemption Amount Of Principal Notes		$ 300,000,000
Mississippi Power [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity		900,000,000
Maximum Borrowing Capacity		1,200,000,000
Remaining Borrowing Capacity		300,000,000
Mississippi Power [Member] | Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Repayments of Senior Debt		$ 900,000,000
Mississippi Power [Member] | Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						10,000,000	10,000,000
Traditional Operating Companies [Member]
Debt Instrument [Line Items]
Fixed rate pollution control revenue bonds outstanding						320,000,000	320,000,000
Southern Power [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity						600,000,000	600,000,000
Senior Note Issuances							1,241,000,000
Capital contributions from parent company							300,000,000	$ 0
Remaining Borrowing Capacity						$ 560,000,000	$ 560,000,000
Southern Power [Member] | Senior Notes [Member] | Series 2016A [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount | €									€ 600,000,000
Debt Instrument, Interest Rate, Stated Percentage						1.00%	1.00%		1.00%
Southern Power [Member] | Senior Notes [Member] | Series 2016B [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount | €									€ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage						1.85%	1.85%		1.85%
Southern Power [Member] | Project Credit Facilities [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity						$ 769,000,000	$ 769,000,000
Debt, Weighted Average Interest Rate						2.02%	2.02%		2.02%
Maximum Borrowing Capacity						$ 769,000,000	$ 769,000,000
Line of Credit Facility, Average Amount Outstanding						$ 586,000,000	586,000,000
Debt Instrument, Interest Rate During Period						2.03%
Southern Power [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity						$ 149,000,000	149,000,000
Remaining Borrowing Capacity						65,000,000	65,000,000
Southern Company [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity						2,250,000,000	2,250,000,000
Senior Note Issuances			$ 8,500,000,000				8,500,000,000
Remaining Borrowing Capacity						$ 2,250,000,000	2,250,000,000
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage			1.55%
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 1,000,000,000
Debt Instrument, Interest Rate, Stated Percentage			1.85%
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 1,500,000,000
Debt Instrument, Interest Rate, Stated Percentage			2.35%
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 1,250,000,000
Debt Instrument, Interest Rate, Stated Percentage			2.95%
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 1,750,000,000
Debt Instrument, Interest Rate, Stated Percentage			3.25%
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage			4.25%
Southern Company [Member] | Senior Notes [Member] | Senior Notes due July 1, 2046 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 2,000,000,000
Debt Instrument, Interest Rate, Stated Percentage			4.40%
Southern Power's Subsidiary(ies) [Member]
Debt Instrument [Line Items]
Proceeds from Long-term Lines of Credit							$ 632,000,000
Southern Power's Subsidiary(ies) [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate						2.00%	2.00%		2.00%
Southern Power's Subsidiary(ies) [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 16,000,000	$ 16,000,000

Retirement Benefits (Details)

Retirement Benefits (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in next fiscal year			$ 0
Pension Plans [Member] | Southern Company [Member]
Pension Plans and Postretirement Plans
Service cost	$ 62,000,000	$ 64,000,000	124,000,000	$ 128,000,000
Interest cost	101,000,000	111,000,000	201,000,000	222,000,000
Expected return on plan assets	(187,000,000)	(181,000,000)	(374,000,000)	(362,000,000)
Amortization:
Prior service costs	3,000,000	7,000,000	7,000,000	13,000,000
Net (gain)/loss	37,000,000	54,000,000	75,000,000	108,000,000
Net cost	16,000,000	55,000,000	33,000,000	109,000,000
Pension Plans [Member] | Alabama Power [Member]
Pension Plans and Postretirement Plans
Service cost	15,000,000	15,000,000	29,000,000	30,000,000
Interest cost	24,000,000	27,000,000	48,000,000	53,000,000
Expected return on plan assets	(46,000,000)	(44,000,000)	(92,000,000)	(89,000,000)
Amortization:
Prior service costs	0	1,000,000	1,000,000	3,000,000
Net (gain)/loss	10,000,000	13,000,000	20,000,000	27,000,000
Net cost	3,000,000	12,000,000	6,000,000	24,000,000
Pension Plans [Member] | Georgia Power [Member]
Pension Plans and Postretirement Plans
Service cost	18,000,000	18,000,000	35,000,000	36,000,000
Interest cost	34,000,000	39,000,000	68,000,000	77,000,000
Expected return on plan assets	(65,000,000)	(63,000,000)	(129,000,000)	(126,000,000)
Amortization:
Prior service costs	2,000,000	2,000,000	3,000,000	5,000,000
Net (gain)/loss	13,000,000	19,000,000	27,000,000	38,000,000
Net cost	2,000,000	15,000,000	4,000,000	30,000,000
Pension Plans [Member] | Gulf Power [Member]
Pension Plans and Postretirement Plans
Service cost	3,000,000	3,000,000	6,000,000	6,000,000
Interest cost	4,000,000	5,000,000	9,000,000	10,000,000
Expected return on plan assets	(8,000,000)	(8,000,000)	(17,000,000)	(16,000,000)
Amortization:
Prior service costs	1,000,000	0	1,000,000	0
Net (gain)/loss	1,000,000	2,000,000	3,000,000	5,000,000
Net cost	1,000,000	2,000,000	2,000,000	5,000,000
Pension Plans [Member] | Mississippi Power [Member]
Pension Plans and Postretirement Plans
Service cost	3,000,000	3,000,000	6,000,000	6,000,000
Interest cost	5,000,000	6,000,000	10,000,000	11,000,000
Expected return on plan assets	(8,000,000)	(9,000,000)	(17,000,000)	(17,000,000)
Amortization:
Prior service costs	0	1,000,000	0	1,000,000
Net (gain)/loss	1,000,000	2,000,000	3,000,000	5,000,000
Net cost	1,000,000	3,000,000	2,000,000	6,000,000
Other Postretirement Benefits [Member] | Southern Company [Member]
Pension Plans and Postretirement Plans
Service cost	6,000,000	5,000,000	11,000,000	11,000,000
Interest cost	17,000,000	20,000,000	35,000,000	39,000,000
Expected return on plan assets	(14,000,000)	(14,000,000)	(28,000,000)	(29,000,000)
Amortization:
Prior service costs	1,000,000	1,000,000	3,000,000	2,000,000
Net (gain)/loss	4,000,000	4,000,000	7,000,000	9,000,000
Net cost	14,000,000	16,000,000	28,000,000	32,000,000
Other Postretirement Benefits [Member] | Alabama Power [Member]
Pension Plans and Postretirement Plans
Service cost	2,000,000	2,000,000	3,000,000	3,000,000
Interest cost	4,000,000	5,000,000	9,000,000	10,000,000
Expected return on plan assets	(7,000,000)	(7,000,000)	(13,000,000)	(13,000,000)
Amortization:
Prior service costs	1,000,000	0	2,000,000	1,000,000
Net (gain)/loss	1,000,000	1,000,000	1,000,000	1,000,000
Net cost	1,000,000	1,000,000	2,000,000	2,000,000
Other Postretirement Benefits [Member] | Georgia Power [Member]
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	3,000,000	3,000,000
Interest cost	7,000,000	9,000,000	15,000,000	17,000,000
Expected return on plan assets	(5,000,000)	(6,000,000)	(11,000,000)	(12,000,000)
Amortization:
Prior service costs	1,000,000	0	1,000,000	0
Net (gain)/loss	2,000,000	3,000,000	4,000,000	6,000,000
Net cost	6,000,000	7,000,000	12,000,000	14,000,000
Other Postretirement Benefits [Member] | Gulf Power [Member]
Pension Plans and Postretirement Plans
Service cost	1,000,000	0	1,000,000	0
Interest cost	0	1,000,000	1,000,000	2,000,000
Expected return on plan assets	(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Amortization:
Prior service costs	0	0	0	0
Net (gain)/loss	0	0	0	0
Net cost	0	0	1,000,000	1,000,000
Other Postretirement Benefits [Member] | Mississippi Power [Member]
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	1,000,000	1,000,000
Interest cost	1,000,000	1,000,000	2,000,000	2,000,000
Expected return on plan assets	(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Amortization:
Prior service costs	0	0	0	0
Net (gain)/loss	0	0	0	0
Net cost	$ 1,000,000	$ 1,000,000	$ 2,000,000	$ 2,000,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 208		$ 188
Effective tax rate	30.40%	32.90%
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits as of December 31, 2015	$ 433
Tax positions from current periods	10
Balance as of June 30, 2016	443
Tax positions impacting the effective tax rate	20		10
Tax positions not impacting the effective tax rate	423		423
Kemper IGCC [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of June 30, 2016	423
Unrecognized tax benefit, associated interest	$ 15
Mississippi Power [Member]
Income Tax Contingency [Line Items]
Effective tax rate	(205.60%)	19.00%
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits as of December 31, 2015	$ 421
Tax positions from current periods	0
Balance as of June 30, 2016	421
Tax positions impacting the effective tax rate	(2)
Tax positions not impacting the effective tax rate	423
Mississippi Power [Member] | Kemper IGCC [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of June 30, 2016	423
Unrecognized tax benefit, associated interest	$ 15
Southern Power [Member]
Income Tax Contingency [Line Items]
Effective tax rate	(74.00%)	13.70%
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits as of December 31, 2015	$ 8
Tax positions from current periods	9
Balance as of June 30, 2016	17
Tax positions impacting the effective tax rate	17
Tax positions not impacting the effective tax rate	0
Investment Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	801		554
Investment Tax Credit Carryforward [Member] | Southern Power [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	784		551
General Business Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	16		1
General Business Tax Credit Carryforward [Member] | Southern Power [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	$ 16		$ 1

Derivatives - Schedule of Deriv

Derivatives - Schedule of Derivatives and Gains (Losses) (Details) BTU in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)BTU
Southern Company [Member] | Gas [Member]
Energy-related derivative contracts
Net Purchased mmBtu | BTU	250
Longest Hedge Date	2,020
Longest Non-Hedge Date	2,016
Alabama Power [Member] | Gas [Member]
Energy-related derivative contracts
Net Purchased mmBtu | BTU	60
Longest Hedge Date	2,019
Georgia Power [Member] | Gas [Member]
Energy-related derivative contracts
Net Purchased mmBtu | BTU	82
Longest Hedge Date	2,019
Gulf Power [Member] | Gas [Member]
Energy-related derivative contracts
Net Purchased mmBtu | BTU	66
Longest Hedge Date	2,020
Mississippi Power [Member] | Gas [Member]
Energy-related derivative contracts
Net Purchased mmBtu | BTU	29
Longest Hedge Date	2,019
Southern Power [Member] | Maturity Date October 2016 [Member] | Not Designated as Hedging Instrument [Member]
Interest rate derivatives
Derivative term	15 years
Southern Power [Member] | Maturity Date November 2016 [Member] | Not Designated as Hedging Instrument [Member]
Interest rate derivatives
Derivative term	12 years
Southern Power [Member] | Gas [Member]
Energy-related derivative contracts
Net Purchased mmBtu | BTU	13
Longest Hedge Date	2,017
Longest Non-Hedge Date	2,016
Interest Rate Contract [Member]
Interest rate derivatives
Notional Amount	$ 1,968
Fair Value Gain (Loss) at June 30, 2016	20
Interest Rate Contract [Member] | Southern Company [Member] | Maturity Date June 2020 Number One [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 8
Weighted Average Interest Rate Paid	1.73%
Fair Value Gain (Loss) at June 30, 2016	$ 0
Interest Rate Contract [Member] | Southern Company [Member] | Maturity Date June 2020 Number Two [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 3
Weighted Average Interest Rate Paid	1.73%
Fair Value Gain (Loss) at June 30, 2016	$ 0
Interest Rate Contract [Member] | Southern Company [Member] | Maturity Date August 2017 [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 250
Interest Rate Received	1.30%
Fair Value Gain (Loss) at June 30, 2016	$ 2
Interest Rate Contract [Member] | Southern Company [Member] | Maturity Date August 2017 [Member] | London Interbank Offered Rate (LIBOR) [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Weighted Average Interest Rate Paid	0.17%
Interest Rate Contract [Member] | Southern Company [Member] | Maturity Date June 2020 [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 300
Interest Rate Received	2.75%
Fair Value Gain (Loss) at June 30, 2016	$ 11
Interest Rate Contract [Member] | Southern Company [Member] | Maturity Date June 2020 [Member] | London Interbank Offered Rate (LIBOR) [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Weighted Average Interest Rate Paid	0.92%
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date August 2016 [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 200
Weighted Average Interest Rate Paid	1.01%
Fair Value Gain (Loss) at June 30, 2016	$ 0
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date August 2016 [Member] | London Interbank Offered Rate (LIBOR) [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Interest Rate Received	0.40%
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date June 2018 [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 250
Interest Rate Received	5.40%
Fair Value Gain (Loss) at June 30, 2016	$ 3
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date June 2018 [Member] | London Interbank Offered Rate (LIBOR) [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Weighted Average Interest Rate Paid	4.02%
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date December 2019 [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 200
Interest Rate Received	4.25%
Fair Value Gain (Loss) at June 30, 2016	$ 6
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date December 2019 [Member] | London Interbank Offered Rate (LIBOR) [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Weighted Average Interest Rate Paid	2.46%
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date December 2018 [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Notional Amount	$ 500
Interest Rate Received	1.95%
Fair Value Gain (Loss) at June 30, 2016	$ 5
Interest Rate Contract [Member] | Georgia Power [Member] | Maturity Date December 2018 [Member] | London Interbank Offered Rate (LIBOR) [Member] | Fair Value Hedges Of Existing Debt [Member]
Interest rate derivatives
Weighted Average Interest Rate Paid	0.76%
Interest Rate Contract [Member] | Gulf Power [Member] | Maturity Date December 2026 [Member] | Cash Flow Hedges Of Forecasted Debt [Member]
Interest rate derivatives
Notional Amount	$ 80
Weighted Average Interest Rate Paid	2.32%
Fair Value Gain (Loss) at June 30, 2016	$ (7)
Interest Rate Contract [Member] | Southern Power [Member] | Maturity Date October 2016 Number One [Member] | Not Designated as Hedging Instrument [Member]
Interest rate derivatives
Notional Amount	$ 65
Weighted Average Interest Rate Paid	2.50%
Fair Value Gain (Loss) at June 30, 2016	$ 0
Interest Rate Contract [Member] | Southern Power [Member] | Maturity Date October 2016 [Member] | Not Designated as Hedging Instrument [Member]
Interest rate derivatives
Notional Amount	$ 47
Weighted Average Interest Rate Paid	2.21%
Fair Value Gain (Loss) at June 30, 2016	$ 0
Interest Rate Contract [Member] | Southern Power [Member] | Maturity Date November 2016 [Member] | Not Designated as Hedging Instrument [Member]
Interest rate derivatives
Notional Amount	$ 65
Weighted Average Interest Rate Paid	2.21%
Fair Value Gain (Loss) at June 30, 2016	$ 0
Foreign Exchange Contract [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Fair Value Gain (Loss) at June 30, 2016	(38)
Foreign Exchange Contract [Member] | Southern Power [Member] | Maturity Date June 2022 [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Fair Value Gain (Loss) at June 30, 2016	(17)
Foreign Exchange Contract [Member] | Southern Power [Member] | Maturity Date June 2026 [Member] | Cash Flow Hedges Of Existing Debt [Member]
Interest rate derivatives
Fair Value Gain (Loss) at June 30, 2016	$ (21)

Derivatives - Foreign Currency

Derivatives - Foreign Currency Derivatives (Details) - 6 months ended Jun. 30, 2016 - Cash Flow Hedges Of Existing Debt [Member] - Foreign Exchange Contract [Member] € in Millions, $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Pay Notional	$ 1,241
Receive Notional | €		€ 1,100
Fair Value Gain (Loss) at June 30, 2016	(38)
Maturity Date June 2022 [Member] | Southern Power [Member]
Derivative [Line Items]
Pay Notional	$ 677
Pay Rate	2.95%
Receive Notional | €		600
Receive Rate	1.00%
Fair Value Gain (Loss) at June 30, 2016	$ (17)
Maturity Date June 2026 [Member] | Southern Power [Member]
Derivative [Line Items]
Pay Notional	$ 564
Pay Rate	3.78%
Receive Notional | €		€ 500
Receive Rate	1.85%
Fair Value Gain (Loss) at June 30, 2016	$ (21)

Derivatives - Balance Sheet Pre

Derivatives - Balance Sheet Presentation (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	$ 1
Southern Company [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	63	$ 29
Derivatives, liabilities	155	250
Southern Company [Member] | Energy Related Derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral	4	1
Derivative liability amount offset against collateral	78	214
Southern Company [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	36	7
Derivatives, liabilities	110	220
Southern Company [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral	32	6
Derivative liability amount not offset against collateral	32	6
Southern Company [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral		13
Derivative liability amount offset against collateral		21
Southern Company [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		22
Derivatives, liabilities		30
Southern Company [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral		9
Derivative liability amount not offset against collateral		9
Southern Company [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		4
Southern Company [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	1
Southern Company [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		1
Southern Company [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		3
Southern Company [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	28
Derivatives, liabilities	105	217
Southern Company [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	12	3
Southern Company [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	16
Southern Company [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	61	130
Southern Company [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	44	87
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	33	22
Derivatives, liabilities	49	32
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	5	3
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	3	2
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	1
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	11	19
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	16
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	7	23
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		7
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	24
Southern Company [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	14
Alabama Power [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	10	1
Derivatives, liabilities	22	70
Alabama Power [Member] | Energy Related Derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral	2	0
Derivative liability amount offset against collateral	14	54
Alabama Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	10	1
Derivatives, liabilities	22	55
Alabama Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral	8	1
Derivative liability amount not offset against collateral	8	1
Alabama Power [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral		0
Derivative liability amount offset against collateral		15
Alabama Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Derivatives, liabilities		15
Alabama Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral		0
Derivative liability amount not offset against collateral		0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	10
Derivatives, liabilities	22	55
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	5	1
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	5
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	17	40
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	5	15
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	15
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	15
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Georgia Power [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	29	7
Derivatives, liabilities	5	21
Georgia Power [Member] | Energy Related Derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral	11	0
Derivative liability amount offset against collateral	1	13
Georgia Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	15	2
Derivatives, liabilities	5	15
Georgia Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral	4	2
Derivative liability amount not offset against collateral	4	2
Georgia Power [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral		1
Derivative liability amount offset against collateral		2
Georgia Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		5
Derivatives, liabilities		6
Georgia Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral		4
Derivative liability amount not offset against collateral		4
Georgia Power [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Georgia Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Georgia Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Georgia Power [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	15
Derivatives, liabilities	5	15
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	6	2
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	9
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	4	12
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	1	3
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	14	5
Derivatives, liabilities	0	6
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	6	5
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	8
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		6
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Gulf Power [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	1
Derivatives, liabilities	62	100
Gulf Power [Member] | Energy Related Derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral	0	0
Derivative liability amount offset against collateral	53	100
Gulf Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	0
Derivatives, liabilities	55	100
Gulf Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral	2	0
Derivative liability amount not offset against collateral	2	0
Gulf Power [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral		1
Derivative liability amount offset against collateral		0
Gulf Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		1
Derivatives, liabilities		0
Gulf Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral		0
Derivative liability amount not offset against collateral		0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	2
Derivatives, liabilities	55	100
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1	0
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	25	49
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	30	51
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	1
Derivatives, liabilities	7	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	1
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	7	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Mississippi Power [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1	0
Derivatives, liabilities	23	47
Mississippi Power [Member] | Energy Related Derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral	0	0
Derivative liability amount offset against collateral	22	47
Mississippi Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1	0
Derivatives, liabilities	23	47
Mississippi Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral	1	0
Derivative liability amount not offset against collateral	1	0
Mississippi Power [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral		0
Derivative liability amount offset against collateral		0
Mississippi Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Derivatives, liabilities		0
Mississippi Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral		0
Derivative liability amount not offset against collateral		0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		0
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1
Derivatives, liabilities	23	47
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	15	29
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	8	18
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0
Southern Power [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	8	7
Derivatives, liabilities	43	3
Southern Power [Member] | Energy Related Derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral	5	3
Derivative liability amount offset against collateral	2	2
Southern Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	8	4
Derivatives, liabilities	5	3
Southern Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral	3	1
Derivative liability amount not offset against collateral	3	1
Southern Power [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount offset against collateral		3
Derivative liability amount offset against collateral		0
Southern Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		3
Derivatives, liabilities		0
Southern Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative asset amount not offset against collateral		0
Derivative liability amount not offset against collateral		0
Southern Power [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		4
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	1
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	1	1
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets		3
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	6	3
Derivatives, liabilities	42	2
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	5	3
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	1
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	3	2
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	1
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other current assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred charges and assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives, assets	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities		$ 0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	24
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other deferred credits and liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	$ 14

Derivatives - Balance Sheet Off

Derivatives - Balance Sheet Offsetting (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Southern Company [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	$ 63	$ 29
Derivatives presented in the Balance Sheet, liabilities	155	250
Southern Company [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Net derivative assets	4	1
Net interest rate derivative liabilities	78	214
Southern Company [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	36	7
Derivatives presented in the Balance Sheet, liabilities	110	220
Southern Company [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(32)	(6)
Gross amounts not offset in the Balance Sheet, liabilities	(32)	(6)
Southern Company [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Net derivative assets	9
Net interest rate derivative liabilities	27
Southern Company [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	27
Derivatives presented in the Balance Sheet, liabilities	45
Southern Company [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(18)
Gross amounts not offset in the Balance Sheet, liabilities	(18)
Alabama Power [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	10	1
Derivatives presented in the Balance Sheet, liabilities	22	70
Alabama Power [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Net derivative assets	2	0
Net interest rate derivative liabilities	14	54
Alabama Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	10	1
Derivatives presented in the Balance Sheet, liabilities	22	55
Alabama Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(8)	(1)
Gross amounts not offset in the Balance Sheet, liabilities	(8)	(1)
Alabama Power [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Net derivative assets	0
Net interest rate derivative liabilities	0
Alabama Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	0
Derivatives presented in the Balance Sheet, liabilities	0
Alabama Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	0
Gross amounts not offset in the Balance Sheet, liabilities	0
Georgia Power [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	29	7
Derivatives presented in the Balance Sheet, liabilities	5	21
Georgia Power [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Net derivative assets	11	0
Net interest rate derivative liabilities	1	13
Georgia Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	15	2
Derivatives presented in the Balance Sheet, liabilities	5	15
Georgia Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(4)	(2)
Gross amounts not offset in the Balance Sheet, liabilities	(4)	(2)
Georgia Power [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Net derivative assets	14
Net interest rate derivative liabilities	0
Georgia Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	14
Derivatives presented in the Balance Sheet, liabilities	0
Georgia Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	0
Gross amounts not offset in the Balance Sheet, liabilities	0
Gulf Power [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	2	1
Derivatives presented in the Balance Sheet, liabilities	62	100
Gulf Power [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Net derivative assets	0	0
Net interest rate derivative liabilities	53	100
Gulf Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	2	0
Derivatives presented in the Balance Sheet, liabilities	55	100
Gulf Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(2)	0
Gross amounts not offset in the Balance Sheet, liabilities	(2)	0
Gulf Power [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Net derivative assets	0
Net interest rate derivative liabilities	7
Gulf Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	0
Derivatives presented in the Balance Sheet, liabilities	7
Gulf Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	0
Gross amounts not offset in the Balance Sheet, liabilities	0
Mississippi Power [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	1	0
Derivatives presented in the Balance Sheet, liabilities	23	47
Mississippi Power [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Net derivative assets	0	0
Net interest rate derivative liabilities	22	47
Mississippi Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	1	0
Derivatives presented in the Balance Sheet, liabilities	23	47
Mississippi Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(1)	0
Gross amounts not offset in the Balance Sheet, liabilities	(1)	0
Mississippi Power [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Net derivative assets	0
Net interest rate derivative liabilities	0
Mississippi Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	0
Derivatives presented in the Balance Sheet, liabilities	0
Mississippi Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	0
Gross amounts not offset in the Balance Sheet, liabilities	0
Southern Power [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	8	7
Derivatives presented in the Balance Sheet, liabilities	43	3
Southern Power [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Net derivative assets	5	3
Net interest rate derivative liabilities	2	2
Southern Power [Member] | Energy Related Derivative [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	8	4
Derivatives presented in the Balance Sheet, liabilities	5	3
Southern Power [Member] | Energy Related Derivative [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	(3)	(1)
Gross amounts not offset in the Balance Sheet, liabilities	(3)	$ (1)
Southern Power [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Net derivative assets	0
Net interest rate derivative liabilities	38
Southern Power [Member] | Interest Rate Contract [Member] | Net Amount Of Derivatives [Member]
Derivative [Line Items]
Derivatives presented in the Balance Sheet, assets	0
Derivatives presented in the Balance Sheet, liabilities	38
Southern Power [Member] | Interest Rate Contract [Member] | Gross Amount Of Derivatives [Member]
Derivative [Line Items]
Gross amounts not offset in the Balance Sheet, assets	0
Gross amounts not offset in the Balance Sheet, liabilities	$ 0

Derivatives - Pre-tax Effects o

Derivatives - Pre-tax Effects of Derivatives Designated as Cash Flow Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	$ (33)	$ 31	$ (223)	$ 2
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(25)	(2)	(28)	(4)
Southern Company [Member] | Energy Related Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(77)		(77)		$ (214)
Southern Company [Member] | Energy Related Derivative [Member] | Other regulatory assets, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(61)		(61)		(130)
Southern Company [Member] | Energy Related Derivative [Member] | Other regulatory assets, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(44)		(44)		(87)
Southern Company [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	12		12		3
Southern Company [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	16		16
Southern Company [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	6	31	(184)	2
Southern Company [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(4)	(2)	(7)	(4)
Southern Company [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(39)	0		0
Southern Company [Member] | Foreign Exchange Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(1)	0	(1)	0
Southern Company [Member] | Foreign Exchange Contract [Member] | Other Income Expense Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(20)		(20)
Alabama Power [Member] | Energy Related Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(12)		(12)		(54)
Alabama Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(17)		(17)		(40)
Alabama Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(5)		(5)		(15)
Alabama Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	5		5		1
Alabama Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	5		5
Alabama Power [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	0	7	(4)	1
Alabama Power [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(2)	(1)	(3)	(1)
Georgia Power [Member] | Energy Related Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	10		10		(13)
Georgia Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(4)		(4)		(12)
Georgia Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(1)		(1)		(3)
Georgia Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	6		6		2
Georgia Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	9		9
Georgia Power [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	0	24	0	1
Georgia Power [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(1)	(1)	(2)	(2)
Gulf Power [Member] | Energy Related Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(53)		(53)		(100)
Gulf Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(25)		(25)		(49)
Gulf Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(30)		(30)		(51)
Gulf Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	1		1		0
Gulf Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	1		1
Gulf Power [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(2)	0	(7)	0
Gulf Power [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	0	0	0
Mississippi Power [Member] | Energy Related Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(22)		(22)		(47)
Mississippi Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(15)		(15)		(29)
Mississippi Power [Member] | Energy Related Derivative [Member] | Other regulatory assets, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	(8)		(8)		(18)
Mississippi Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, current [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	0		0		$ 0
Mississippi Power [Member] | Energy Related Derivative [Member] | Other regulatory liabilities, deferred [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Hedge Unrealized Gain (Loss) Recognized on the Balance Sheet	1		1
Mississippi Power [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)			0	0
Mississippi Power [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)			(1)	(1)
Southern Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(39)	0	(39)	0
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(21)	0	(22)	0
Southern Power [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)			0	0
Southern Power [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)			(1)	0
Southern Power [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(39)	0	(39)	0
Southern Power [Member] | Foreign Exchange Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(1)	$ 0	(1)	$ 0
Southern Power [Member] | Foreign Exchange Contract [Member] | Other Income Expense Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (20)		$ (20)

Derivatives - Pre-tax Effects54

Derivatives - Pre-tax Effects of Derivatives as Fair Value Hedging Relationships (Details) - Interest Rate Contract [Member] - Interest Expense [Member] - Fair Value Hedging [Member] - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Southern Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value, Gross Asset	$ 24	$ 4
Georgia Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value, Gross Asset	$ 15	$ 2

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) BTU in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)BTU
Derivative [Line Items]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months	$ (24)
Maximum Potential Collateral Requirements Arising from Credit Risk Related Contingent Features	$ 24
Southern Company [Member]
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | BTU	3

Acquisitions - Schedule of Acqu

Acquisitions - Schedule of Acquisitions (Details) $ in Millions	Jul. 01, 2016MW	Jun. 30, 2016USD ($)MW	Apr. 07, 2016MW	Mar. 04, 2016MW	Feb. 11, 2016MW	Dec. 31, 2015USD ($)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill		$ 264				$ 2
Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill		2				$ 2
Southern Company Gas [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Current assets		1,474
Property, plant, and equipment		9,795
Goodwill		6,333
Intangible assets		436
Regulatory assets		846
Other assets		273
Current liabilities		(2,205)
Deferred credits and other liabilities		(4,529)
Long-term debt		(4,261)
Noncontrolling interests		(160)
Total purchase price		8,002
PowerSecure International, Inc. [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Current assets		174
Property, plant, and equipment		48
Goodwill		262
Intangible assets		99
Other assets		8
Current liabilities		(111)
Long-term debt, including current portion		(47)
Deferred credits and other liabilities		(4)
Total purchase price		$ 429
Calipatria [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Solar (MW) | MW					20
Southern Power Percentage Ownership					90.00%
PPA Contract Period					20 years
East Pecos [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Solar (MW) | MW				120
Southern Power Percentage Ownership				100.00%
PPA Contract Period				15 years
Grant Wind, LLC [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Wind (MW) | MW			151
Southern Power Percentage Ownership			100.00%
PPA Contract Period			20 years
Passadumkeag [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Wind (MW) | MW		42
Southern Power Percentage Ownership		100.00%
PPA Contract Period		15 years
Henrietta [Member] | Subsequent Event [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Solar (MW) | MW	102
Southern Power Percentage Ownership	51.00%
PPA Contract Period	20 years
Lamesa [Member] | Subsequent Event [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Solar (MW) | MW	102
Southern Power Percentage Ownership	100.00%
PPA Contract Period	15 years
Rutherford [Member] | Subsequent Event [Member] | Southern Power [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Approx. Nameplate Capacity, Solar (MW) | MW	74
Southern Power Percentage Ownership	90.00%
PPA Contract Period	15 years
Series of Business Acquisitions [Member] | Southern Power [Member] | Class A Membership Interest [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Southern Power Percentage Ownership		100.00%
Percentage Of Entitled Cash Distributions		51.00%
Series of Business Acquisitions [Member] | SunPower Corp. [Member] | Class B Membership Interest [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Percentage Of Entitled Cash Distributions		49.00%
Series of Business Acquisitions [Member] | Recurrent Energy [Member] | Class B Membership Interest [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Southern Power Percentage Ownership		100.00%

Acquisitions - Schedule of Cons

Acquisitions - Schedule of Construction Projects (Details) - MW	Jul. 19, 2016	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2016	Aug. 08, 2016	Jun. 30, 2016	Mar. 29, 2016	Dec. 31, 2015
Southern Power [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership							15.00%
Capacity Of Small Power Production Facility						152		110
Class A Membership Interest [Member] | Southern Power [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Percentage Of Entitled Cash Distributions							66.00%
Class B Membership Interest [Member] | First Solar [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Percentage Of Entitled Cash Distributions							34.00%
Subsequent Event [Member] | Southern Power [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Capacity Of Small Power Production Facility					37
Subsequent Event [Member] | Southern Power [Member] | RE Tranquility Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW)	205
PPA Contract Period	18 years
Scenario, Forecast [Member] | Southern Power [Member] | Butler Solar LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW)		103
PPA Contract Period		30 years
Scenario, Forecast [Member] | Southern Power [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW)			299	299
PPA Contract Period				20 years
Scenario, Forecast [Member] | Southern Power [Member] | RE Garland and Garland A Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW)		205
Scenario, Forecast [Member] | Southern Power [Member] | RE Garland Holdings, LLC [Member]
Business Acquisition [Line Items]
PPA Contract Period		15 years
Scenario, Forecast [Member] | Southern Power [Member] | RE Garland and Garland A Holdings, LLC [Member]
Business Acquisition [Line Items]
PPA Contract Period			20 years
Scenario, Forecast [Member] | Southern Power [Member] | RE Roserock Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW)		160
PPA Contract Period		20 years
Scenario, Forecast [Member] | Southern Power [Member] | Sandhills [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW)		146
PPA Contract Period		25 years

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ / shares in Units, $ in Millions	Aug. 08, 2016USD ($)	Jul. 10, 2016USD ($)mi	Jul. 01, 2016USD ($)MW	May 09, 2016USD ($)$ / shares	Apr. 07, 2016MW	Mar. 04, 2016MW	Feb. 11, 2016MW	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)entitiesMW	Jun. 30, 2016USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Goodwill								$ 264		$ 264	$ 2
Construction work in progress								9,451		9,451	9,082
Property, Plant and Equipment, Gross								78,112		78,112	75,118
Other Assets, Current								71		71	71
Southern Power [Member]
Business Acquisition [Line Items]
Aggregate purchase price										477
Goodwill								2		2	2
Total costs of construction										2,700
Construction work in progress								1,852		1,852	1,137
Contingent consideration								23		23	36
Property, Plant and Equipment, Gross								8,348		8,348	7,275
Other Assets, Current								31		31	30
Accounts Payable, Other, Current								175		175	$ 327
Southern Power and Turner Renewable Energy [Member]
Business Acquisition [Line Items]
Aggregate purchase price										483
Subsequent Event [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Aggregate purchase price	$ 275
Subsequent Event [Member] | Southern Power and Turner Renewable Energy [Member]
Business Acquisition [Line Items]
Aggregate purchase price	447
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	217
Subsequent Event [Member] | Minimum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments	260
Subsequent Event [Member] | Maximum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments	$ 300
Southern Company Gas [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities								2,205		2,205
Goodwill								6,333		6,333
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net								8,002		8,002
Southern Company Gas [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Aggregate purchase price			$ 8,000
Southern Company Gas [Member] | Bridge Agreement [Member]
Business Acquisition [Line Items]
Acquisition-related costs								43.4		63.3
Southern Company Gas [Member] | Bridge Agreement [Member] | Operating Expense [Member]
Business Acquisition [Line Items]
Acquisition-related costs								26.9		32.9
Southern Company Gas [Member] | Bridge Agreement [Member] | Other Income Expense Net [Member]
Business Acquisition [Line Items]
Acquisition-related costs								16.5		30.4
PowerSecure International, Inc. [Member]
Business Acquisition [Line Items]
Aggregate purchase price				$ 429
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities								111		111
Acquisition, share price (in dollars per share) | $ / shares				$ 18.75
Goodwill								262		262
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net								429		$ 429
PowerSecure International, Inc. [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated lives of intangible assets										3 years
PowerSecure International, Inc. [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated lives of intangible assets										26 years
Southern Natural Gas Company, LLC [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Aggregate purchase price		$ 1,500
Ownership percentage		50.00%
Pipeline Infrastructure (in miles) | mi		7,600
Grant Wind, LLC [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage					100.00%
Approx. Nameplate Capacity, Wind (MW) | MW					151
Life Output Of Plant					20 years
East Pecos [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage						100.00%
Approx. Nameplate Capacity, Solar (MW) | MW						120
Life Output Of Plant						15 years
East Pecos [Member] | Minimum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments								160		$ 160
East Pecos [Member] | Maximum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments								180		180
Series of Business Acquisitions [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Revenue of acquirees, actual										4
Construction work in progress								426		426
Contingent consideration								6		6
Property, Plant and Equipment, Gross								58		58
Other Assets, Current								4		4
Accounts Payable, Other, Current								7		7
Series of Construction Projects [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Construction work in progress								1,700		1,700
Series of Construction Projects [Member] | Minimum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments								3,000		3,000
Series of Construction Projects [Member] | Maximum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments								$ 3,200		$ 3,200
Calipatria [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage							90.00%
Approx. Nameplate Capacity, Solar (MW) | MW							20
Life Output Of Plant							20 years
Calipatria [Member] | Turner Renewable Energy [Member]
Business Acquisition [Line Items]
Ownership percentage								10.00%		10.00%
Henrietta [Member] | Subsequent Event [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage			51.00%
Approx. Nameplate Capacity, Solar (MW) | MW			102
Life Output Of Plant			20 years
Henrietta [Member] | Subsequent Event [Member] | SunPower AssetCo, LLC [Member]
Business Acquisition [Line Items]
Ownership percentage	49.00%
Rutherford [Member] | Subsequent Event [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage			90.00%
Approx. Nameplate Capacity, Solar (MW) | MW			74
Life Output Of Plant			15 years
Rutherford [Member] | Subsequent Event [Member] | Turner Renewable Energy [Member]
Business Acquisition [Line Items]
Ownership percentage	10.00%
Scenario, Forecast [Member] | Series of Business Acquisitions [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Aggregate purchase price									$ 1,100
Scenario, Forecast [Member] | Series of Business Acquisitions, Wind [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage									100.00%
Number of Businesses Acquired | entities									2
Approx. Nameplate Capacity, Wind (MW) | MW									299
Scenario, Forecast [Member] | Series of Business Acquisitions, Wind [Member] | Minimum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Life Output Of Plant									12 years
Scenario, Forecast [Member] | Series of Business Acquisitions, Wind [Member] | Maximum [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Life Output Of Plant									14 years
Scenario, Forecast [Member] | Business Acquisition, Wind [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage									90.10%
Approx. Nameplate Capacity, Wind (MW) | MW									257
Life Output Of Plant									12 years
Scenario, Forecast [Member] | Boulder 1 [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage									51.00%
Approx. Nameplate Capacity, Solar (MW) | MW									100
Life Output Of Plant									20 years
Class A Membership Interest [Member] | Series of Business Acquisitions [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage								100.00%		100.00%
Class A Membership Interest [Member] | Scenario, Forecast [Member] | Boulder 1 [Member] | Southern Power [Member]
Business Acquisition [Line Items]
Ownership percentage									100.00%

Segment and Related Informati59

Segment and Related Information - Financial Data for Business Segments (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016USD ($)state	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)state	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of States in which Entity Operates | state	4		4
Operating revenues	$ 4,459	$ 4,337	$ 8,451	$ 8,520
Segment net income (loss)	612	629	1,097	1,138
Total assets	90,873		90,873		$ 78,318
Kemper IGCC [Member]
Segment Reporting Information [Line Items]
Pre-Tax Charge To Income	81	23	134	32
After Tax Charge To Income	50	14	83	20
Electric Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	4,379	4,324	8,360	8,496
Segment net income (loss)	684	607	1,198	1,117
Total assets	81,363		81,363		77,560
Intersegment Eliminations [Member] | Electric Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	(109)	(90)	(212)	(213)
Segment net income (loss)	0	0	0	0
Total assets	(425)		(425)		(397)
Consolidation Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(45)	(30)	(81)	(59)
Segment net income (loss)	(4)	4	(7)	0
Total assets	(995)		(995)		(1,061)
Traditional Operating Companies [Member] | Electric Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	4,115	4,077	7,884	8,025
Segment net income (loss)	595	561	1,059	1,038
Total assets	70,706		70,706		69,052
Southern Power [Member]
Segment Reporting Information [Line Items]
Operating revenues	107	85	204	199
Southern Power [Member] | Electric Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues	373	337	688	684
Segment net income (loss)	89	46	139	79
Total assets	11,082		11,082		8,905
All Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	125	43	172	83
Segment net income (loss)	(68)	$ 18	(94)	$ 21
Total assets	$ 10,505		$ 10,505		$ 1,819

Segment and Related Informati60

Segment and Related Information - Financial Data for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue from External Customer [Line Items]
Electric Utilities' Revenues	$ 4,379	$ 4,324	$ 8,360	$ 8,496
Retail [Member]
Revenue from External Customer [Line Items]
Electric Utilities' Revenues	3,748	3,714	7,124	7,256
Wholesale [Member]
Revenue from External Customer [Line Items]
Electric Utilities' Revenues	446	448	842	915
Other [Member]
Revenue from External Customer [Line Items]
Electric Utilities' Revenues	$ 185	$ 162	$ 394	$ 325