Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Activities:
Net Income	$ 2,415,000,000	$ 2,268,000,000	$ 2,040,000,000
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	2,145,000,000	2,048,000,000	1,831,000,000
Deferred income taxes	1,096,000,000	1,155,000,000	1,038,000,000
Mark-to-market adjustments	(52,000,000)
Allowance for equity funds used during construction	(143,000,000)	(153,000,000)	(194,000,000)
Pension, postretirement, and other employee benefits	(398,000,000)	(45,000,000)	(614,000,000)
Stock based compensation expense	55,000,000	42,000,000	33,000,000
Generation construction screening costs	0	0	(51,000,000)
Retail fuel cost-recovery - long-term	123,000,000	0	0
Other, net	56,000,000	15,000,000	(33,000,000)
Changes in certain current assets and liabilities --
-Receivables	234,000,000	362,000,000	80,000,000
-Fossil fuel stock	(452,000,000)	(62,000,000)	135,000,000
-Materials and supplies	(97,000,000)	(60,000,000)	(30,000,000)
-Other current assets	(37,000,000)	(17,000,000)	(17,000,000)
-Accounts payable	(89,000,000)	(5,000,000)	4,000,000
-Accrued taxes	(71,000,000)	330,000,000	(308,000,000)
-Accrued compensation	(28,000,000)	10,000,000	180,000,000
Increase (Decrease) Retail Fuel Cost Over Recovery Short Term	129,000,000	(3,000,000)	(178,000,000)
-Other current liabilities	(40,000,000)	18,000,000	75,000,000
Net cash provided from operating activities	4,898,000,000	5,903,000,000	3,991,000,000
Investing Activities:
Property additions	(4,809,000,000)	(4,525,000,000)	(4,086,000,000)
Payments for Investment in Restricted Cash	(280,000,000)	1,000,000	(50,000,000)
Distribution of restricted cash	284,000,000	63,000,000	25,000,000
Nuclear decommissioning trust fund purchases	(1,046,000,000)	(2,195,000,000)	(2,009,000,000)
Nuclear decommissioning trust fund sales	1,043,000,000	2,190,000,000	2,004,000,000
Cost of removal, net of salvage	(149,000,000)	(93,000,000)	(125,000,000)
Change in construction payables	(84,000,000)	198,000,000	29,000,000
Other investing activities	(127,000,000)	178,000,000	(44,000,000)
Net cash used for investing activities	(5,168,000,000)	(4,183,000,000)	(4,256,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	(30,000,000)	(438,000,000)	659,000,000
Proceeds --
Long-term debt issuances	4,404,000,000	3,719,000,000	3,151,000,000
Interest Bearing Refundable Deposit Related to Asset Sale	150,000,000	0	0
Common stock issuances	397,000,000	723,000,000	772,000,000
Redemptions and repurchases --
Long-term debt	(3,169,000,000)	(3,170,000,000)	(2,966,000,000)
Payments for Repurchase of Common Stock	(430,000,000)	0	0
Payment of common stock dividends	(1,693,000,000)	(1,601,000,000)	(1,496,000,000)
Payment of dividends on preferred and preference stock of subsidiaries	(65,000,000)	(65,000,000)	(65,000,000)
Other financing activities	19,000,000	(20,000,000)	(33,000,000)
Net cash provided from (used for) financing activities	(417,000,000)	(852,000,000)	22,000,000
Net Change in Cash and Cash Equivalents	(687,000,000)	868,000,000	(243,000,000)
Cash and Cash Equivalents at Beginning of Year	1,315,000,000	447,000,000	690,000,000
Cash and Cash Equivalents at End of Year	628,000,000	1,315,000,000	447,000,000
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	803,000,000	832,000,000	789,000,000
Income taxes (net of refunds)	38,000,000	(401,000,000)	276,000,000
Southern Power [Member]
Operating Activities:
Net Income	175,285,000	162,231,000	131,309,000
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	153,635,000	138,787,000	133,109,000
Deferred income taxes	228,780,000	4,481,000	64,530,000
Investment tax credits received	45,047,000	84,723,000	26,400,000
Deferred revenues	12,633,000	10,594,000	5,586,000
Loss (gain) on sale of property	0	0	478,000
Mark-to-market adjustments	(9,275,000)	8,000,000	1,492,000
Loss on extinguishment of debt	0	19,806,000	0
Other, net	3,104,000	495,000	6,078,000
Changes in certain current assets and liabilities --
-Receivables	(1,384,000)	10,448,000	(23,198,000)
-Fossil fuel stock	(8,578,000)	532,000	2,604,000
-Materials and supplies	(7,825,000)	(4,097,000)	443,000
-Prepaid income taxes	(3,223,000)	10,693,000	4,784,000
-Other current assets	(1,624,000)	(485,000)	(985,000)
-Accounts payable	10,514,000	(6,138,000)	1,469,000
-Accrued taxes	431,000	2,134,000	(16,024,000)
Accrued interest	385,000	(8,102,000)	53,000
-Other current liabilities	492,000	(535,000)	362,000
Net cash provided from operating activities	573,131,000	412,379,000	326,840,000
Investing Activities:
Property additions	(116,633,000)	(254,725,000)	(299,602,000)
Cash paid for acquisitions	(124,059,000)	0	(105,042,000)
Proceeds from property sales	0	25,000	4,000,000
Change in construction payables, net of joint owner portion	(27,387,000)	(14,291,000)	34,851,000
Payments pursuant to long-term service agreements	(63,932,000)	(57,969,000)	(41,598,000)
Other investing activities	(446,000)	(1,412,000)	(721,000)
Net cash used for investing activities	(332,457,000)	(328,372,000)	(408,112,000)
Financing Activities:
Increase (decrease) in notes payable, net	(108,552,000)	(90,267,000)	150,840,000
Proceeds --
Capital contributions from parent company	(662,000)	127,241,000	36,507,000
Senior note issuances	0	575,000,000	0
Other long-term debt issuances	5,470,000	0	4,759,000
Redemptions and repurchases --
Senior notes	0	(575,000,000)	0
Other long-term debt	(2,450,000)	(3,691,000)	0
Premium for early debt extinguishment	0	(19,375,000)	0
Payment of common stock dividends	(127,000,000)	(91,200,000)	(107,100,000)
Other financing activities	4,169,000	(3,976,000)	3,318,000
Net cash provided from (used for) financing activities	(229,025,000)	(81,268,000)	88,324,000
Net Change in Cash and Cash Equivalents	11,649,000	2,739,000	7,052,000
Cash and Cash Equivalents at Beginning of Year	16,943,000	14,204,000	7,152,000
Cash and Cash Equivalents at End of Year	28,592,000	16,943,000	14,204,000
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	50,248,000	74,989,000	63,229,000
Income taxes (net of refunds)	(175,269,000)	(26,486,000)	(6,246,000)
Noncash transactions - accrued property additions at year-end	11,203,000	32,590,000	46,764,000
Mississippi Power [Member]
Operating Activities:
Net Income	149,840,000	95,915,000	81,950,000
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	86,981,000	83,787,000	82,294,000
Deferred income taxes	47,523,000	71,764,000	37,557,000
Investment tax credits received	82,464,000	0	22,173,000
Allowance for equity funds used during construction	(64,793,000)	(24,707,000)	(3,795,000)
Pension, postretirement, and other employee benefits	(35,425,000)	3,169,000	(34,911,000)
Stock based compensation expense	2,084,000	1,548,000	1,186,000
Generation construction screening costs	0	0	(50,554,000)
Hedge settlements	(15,983,000)	848,000	0
Regulatory assets associated with Kemper IGCC	(15,445,000)	(7,719,000)	(12,292,000)
Other, net	10,516,000	(433,000)	8,888,000
Changes in certain current assets and liabilities --
-Receivables	(6,589,000)	5,864,000	(8,185,000)
-Fossil fuel stock	(36,206,000)	(27,933,000)	14,997,000
-Materials and supplies	(3,473,000)	(2,116,000)	(879,000)
-Prepaid income taxes	(3,852,000)	12,907,000	(17,075,000)
-Other current assets	(19,851,000)	1,606,000	(4,633,000)
-Accounts payable	8,814,000	24,143,000	(12,630,000)
-Accrued taxes	13,768,000	1,209,000	(4,268,000)
Accrued interest	17,627,000	6,817,000	194,000
-Accrued compensation	(183,000)	(187,000)	2,291,000
-Over recovered regulatory clause revenues	16,836,000	(16,544,000)	28,450,000
-Other current liabilities	757,000	1,557,000	1,943,000
Net cash provided from operating activities	235,410,000	231,495,000	132,701,000
Investing Activities:
Property additions	(1,620,047,000)	(964,233,000)	(247,005,000)
Cash paid for acquisitions	0	(84,803,000)	0
Investment in restricted cash from pollution control bonds	0	0	(50,000,000)
Distribution of restricted cash	0	50,000,000	0
Cost of removal, net of salvage	(4,355,000)	(7,432,000)	(9,240,000)
Change in construction payables	78,961,000	97,079,000	33,767,000
Capital grant proceeds	13,372,000	232,442,000	23,657,000
Other investing activities	(16,706,000)	(5,736,000)	(5,587,000)
Net cash used for investing activities	(1,548,775,000)	(682,683,000)	(254,408,000)
Proceeds --
Interest Bearing Refundable Deposit Related to Asset Sale	150,000,000	0	0
Capital contributions from parent company	702,971,000	299,305,000	65,215,000
Senior note issuances	600,000,000	300,000,000	0
Other long-term debt issuances	50,000,000	115,000,000	225,000,000
Proceeds From Bonds Other	51,471,000	0	0
Redemptions and repurchases --
Capital leases	(633,000)	(1,437,000)	(1,330,000)
Senior notes	(90,000,000)	0	0
Other long-term debt	(115,000,000)	(130,000,000)	0
Payment of preferred and preference stock dividends	(1,733,000)	(1,733,000)	(1,733,000)
Payment of common stock dividends	(106,800,000)	(75,500,000)	(68,600,000)
Other financing activities	6,512,000	(3,641,000)	(1,091,000)
Net cash provided from (used for) financing activities	1,246,788,000	501,994,000	217,461,000
Net Change in Cash and Cash Equivalents	(66,577,000)	50,806,000	95,754,000
Cash and Cash Equivalents at Beginning of Year	211,585,000	160,779,000	65,025,000
Cash and Cash Equivalents at End of Year	145,008,000	211,585,000	160,779,000
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	32,589,000	14,814,000	19,518,000
Income taxes (net of refunds)	(77,580,000)	(41,024,000)	7,546,000
Noncash transactions - accrued property additions at year-end	214,863,000	135,902,000	37,736,000
Assumption of debt due to plant acquisition	0	346,051,000	0
Gulf Power [Member]
Operating Activities:
Net Income	132,135,000	111,208,000	127,714,000
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	147,723,000	135,790,000	127,897,000
Deferred income taxes	174,305,000	63,228,000	82,681,000
Allowance for equity funds used during construction	(5,221,000)	(9,914,000)	(7,213,000)
Pension, postretirement, and other employee benefits	(8,109,000)	(356,000)	(23,964,000)
Stock based compensation expense	1,647,000	1,318,000	1,101,000
Hedge settlements	0	0	1,530,000
Other, net	4,518,000	(8,258,000)	(4,126,000)
Changes in certain current assets and liabilities --
-Receivables	8,713,000	21,518,000	(36,687,000)
-Prepayments	417,000	10,150,000	(10,796,000)
-Fossil fuel stock	(6,144,000)	17,519,000	15,766,000
-Materials and supplies	(3,035,000)	(5,073,000)	(6,251,000)
-Prepaid income taxes	355,000	26,901,000	(29,630,000)
-Property damage cost recovery	(3,500,000)	(3,500,000)	(3,500,000)
-Other current assets	0	40,000	55,000
-Accounts payable	(5,195,000)	(2,528,000)	15,683,000
-Accrued taxes	(4,705,000)	1,475,000	1,427,000
-Accrued compensation	481,000	25,000	5,122,000
-Over recovered regulatory clause revenues	(10,858,000)	10,247,000	3,192,000
-Other current liabilities	(7,837,000)	2,937,000	4,279,000
Net cash provided from operating activities	419,190,000	376,227,000	267,780,000
Investing Activities:
Property additions	(313,257,000)	(324,372,000)	(285,793,000)
Distribution of restricted cash from pollution control revenue bonds	0	0	6,347,000
Cost of removal, net of salvage	(28,993,000)	(14,471,000)	(1,145,000)
Change in construction payables	1,161,000	2,902,000	(21,581,000)
Payments pursuant to long-term service agreements	(8,119,000)	(8,007,000)	(6,011,000)
Other investing activities	656,000	420,000	(262,000)
Net cash used for investing activities	(348,552,000)	(343,528,000)	(308,445,000)
Financing Activities:
Increase (decrease) in notes payable, net	16,075,000	21,324,000	4,451,000
Proceeds --
Capital contributions from parent company	2,106,000	2,101,000	2,242,000
Pollution control revenue bonds issuances and remarketings	13,000,000	0	21,000,000
Common stock issuances	40,000,000	50,000,000	50,000,000
Senior note issuances	100,000,000	125,000,000	300,000,000
Redemptions and repurchases --
Pollution control revenue bonds	(13,000,000)	0	0
Senior notes	(91,363,000)	(608,000)	(215,515,000)
Other long-term debt	0	(110,000,000)	0
Payment of preferred and preference stock dividends	(6,203,000)	(6,203,000)	(6,203,000)
Payment of common stock dividends	(115,800,000)	(110,000,000)	(104,300,000)
Other financing activities	(614,000)	(3,419,000)	(3,253,000)
Net cash provided from (used for) financing activities	(55,799,000)	(31,805,000)	48,422,000
Net Change in Cash and Cash Equivalents	14,839,000	894,000	7,757,000
Cash and Cash Equivalents at Beginning of Year	17,328,000	16,434,000	8,677,000
Cash and Cash Equivalents at End of Year	32,167,000	17,328,000	16,434,000
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	58,255,000	55,486,000	42,521,000
Income taxes (net of refunds)	(96,639,000)	(26,345,000)	17,224,000
Noncash transactions - accrued property additions at year-end	27,369,000	19,439,000	14,475,000
Georgia Power [Member]
Operating Activities:
Net Income	1,185,000,000	1,162,000,000	967,000,000
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	912,000,000	867,000,000	724,000,000
Deferred income taxes	377,000,000	500,000,000	342,000,000
Allowance for equity funds used during construction	(53,000,000)	(96,000,000)	(147,000,000)
Pension, postretirement, and other employee benefits	21,000,000	(15,000,000)	21,000,000
Pension and postretirement funding	(12,000,000)	(15,000,000)	(195,000,000)
Retail fuel cost-recovery - long-term	123,000,000	0	0
Other, net	(12,000,000)	(22,000,000)	(93,000,000)
Changes in certain current assets and liabilities --
-Receivables	205,000,000	235,000,000	168,000,000
-Fossil fuel stock	(269,000,000)	(99,000,000)	103,000,000
-Prepaid income taxes	(7,000,000)	72,000,000	(36,000,000)
-Other current assets	(53,000,000)	(21,000,000)	(9,000,000)
-Accounts payable	(165,000,000)	44,000,000	(99,000,000)
-Accrued taxes	(76,000,000)	(36,000,000)	31,000,000
-Accrued compensation	(18,000,000)	7,000,000	62,000,000
Increase (Decrease) Retail Fuel Cost Over Recovery Short Term	107,000,000	0	0
-Other current liabilities	30,000,000	49,000,000	8,000,000
Net cash provided from operating activities	2,295,000,000	2,632,000,000	1,847,000,000
Investing Activities:
Property additions	(1,723,000,000)	(1,861,000,000)	(2,190,000,000)
Investment in restricted cash from pollution control bonds	(284,000,000)	0	0
Distribution of restricted cash from pollution control revenue bonds	284,000,000	0	0
Nuclear decommissioning trust fund purchases	(852,000,000)	(1,845,000,000)	(1,772,000,000)
Nuclear decommissioning trust fund sales	850,000,000	1,841,000,000	1,768,000,000
Cost of removal, net of salvage	(82,000,000)	(42,000,000)	(67,000,000)
Change in construction payables, net of joint owner portion	(149,000,000)	123,000,000	36,000,000
Other investing activities	(17,000,000)	(7,000,000)	(19,000,000)
Net cash used for investing activities	(1,973,000,000)	(1,791,000,000)	(2,244,000,000)
Financing Activities:
Increase (decrease) in notes payable, net	(513,000,000)	(61,000,000)	252,000,000
Proceeds --
Capital contributions from parent company	42,000,000	214,000,000	688,000,000
Pollution control revenue bonds issuances and remarketings	284,000,000	604,000,000	0
Senior note issuances	2,300,000,000	550,000,000	1,950,000,000
Other long-term debt issuances	0	250,000,000	0
Redemptions and repurchases --
Pollution control revenue bonds	(284,000,000)	(339,000,000)	(516,000,000)
Senior notes	(850,000,000)	(427,000,000)	(1,112,000,000)
Other long-term debt	(250,000,000)	(303,000,000)	0
Long-term debt to affiliate trust	0	(206,000,000)	0
Payment of preferred and preference stock dividends	(17,000,000)	(17,000,000)	(18,000,000)
Payment of common stock dividends	(983,000,000)	(1,096,000,000)	(820,000,000)
Other financing activities	(19,000,000)	(5,000,000)	(33,000,000)
Net cash provided from (used for) financing activities	(290,000,000)	(836,000,000)	391,000,000
Net Change in Cash and Cash Equivalents	32,000,000	5,000,000	(6,000,000)
Cash and Cash Equivalents at Beginning of Year	13,000,000	8,000,000	14,000,000
Cash and Cash Equivalents at End of Year	45,000,000	13,000,000	8,000,000
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	337,000,000	346,000,000	339,000,000
Income taxes (net of refunds)	312,000,000	54,000,000	149,000,000
Noncash transactions - accrued property additions at year-end	261,000,000	391,000,000	310,000,000
Alabama Power [Member]
Operating Activities:
Net Income	743,000,000	747,000,000	746,000,000
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	767,000,000	749,000,000	694,000,000
Deferred income taxes	164,000,000	459,000,000	410,000,000
Mark-to-market adjustments	(36,000,000)
Allowance for equity funds used during construction	(19,000,000)	(22,000,000)	(36,000,000)
Pension, postretirement, and other employee benefits	(11,000,000)	(32,000,000)	(15,000,000)
Pension and postretirement funding	(10,000,000)	(9,000,000)	(55,000,000)
Stock based compensation expense	9,000,000	6,000,000	5,000,000
Natural disaster reserve	3,000,000	34,000,000	52,000,000
Other, net	(27,000,000)	(41,000,000)	(27,000,000)
Changes in certain current assets and liabilities --
-Receivables	23,000,000	18,000,000	(29,000,000)
-Fossil fuel stock	(132,000,000)	47,000,000	(1,000,000)
-Materials and supplies	(21,000,000)	(33,000,000)	(20,000,000)
-Other current assets	(4,000,000)	(6,000,000)	(4,000,000)
-Accounts payable	(77,000,000)	11,000,000	(54,000,000)
-Accrued taxes	(12,000,000)	157,000,000	(140,000,000)
-Accrued compensation	(3,000,000)	(12,000,000)	28,000,000
-Other current liabilities	(17,000,000)	(25,000,000)	(181,000,000)
Net cash provided from operating activities	1,376,000,000	2,048,000,000	1,373,000,000
Investing Activities:
Property additions	(867,000,000)	(977,000,000)	(903,000,000)
Investment in restricted cash from pollution control bonds	1,000,000	4,000,000	0
Distribution of restricted cash	0	13,000,000	18,000,000
Nuclear decommissioning trust fund purchases	(194,000,000)	(350,000,000)	(237,000,000)
Nuclear decommissioning trust fund sales	193,000,000	349,000,000	236,000,000
Cost of removal, net of salvage	(33,000,000)	(28,000,000)	(44,000,000)
Change in construction payables	12,000,000	(9,000,000)	(45,000,000)
Other investing activities	(46,000,000)	9,000,000	(12,000,000)
Net cash used for investing activities	(934,000,000)	(989,000,000)	(987,000,000)
Proceeds --
Capital contributions from parent company	27,000,000	12,000,000	28,000,000
Senior note issuances	1,000,000,000	700,000,000	250,000,000
Redemptions and repurchases --
Pollution control revenue bonds	(1,000,000)	(4,000,000)	0
Senior notes	(950,000,000)	(750,000,000)	(250,000,000)
Payment of preferred and preference stock dividends	(39,000,000)	(39,000,000)	(39,000,000)
Payment of common stock dividends	(684,000,000)	(774,000,000)	(586,000,000)
Other financing activities	(2,000,000)	(14,000,000)	(3,000,000)
Net cash provided from (used for) financing activities	(649,000,000)	(869,000,000)	(600,000,000)
Net Change in Cash and Cash Equivalents	(207,000,000)	190,000,000	(214,000,000)
Cash and Cash Equivalents at Beginning of Year	344,000,000	154,000,000	368,000,000
Cash and Cash Equivalents at End of Year	137,000,000	344,000,000	154,000,000
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	273,000,000	286,000,000	288,000,000
Income taxes (net of refunds)	309,000,000	(139,000,000)	188,000,000
Noncash transactions - accrued property additions at year-end	$ 31,000,000	$ 19,000,000	$ 28,000,000