Consolidated Statements of Capitalization (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Variable rate, Due 2018 through 2052	Dec. 31, 2011 Variable rate, Due 2018 through 2052	Dec. 31, 2012 2019 through 2049	Dec. 31, 2011 2019 through 2049	Dec. 31, 2012 Variable rate, Due 2016	Dec. 31, 2011 Variable rate, Due 2016	Dec. 31, 2012 Maturity Of Pollution Control Bonds Variable Rate Due Two Thousand Seventeen [Member]	Dec. 31, 2011 Maturity Of Pollution Control Bonds Variable Rate Due Two Thousand Seventeen [Member]	Dec. 31, 2012 Variable rate, Due 2015	Dec. 31, 2011 Variable rate, Due 2015	Dec. 31, 2012 Variable rate due 2042	Dec. 31, 2011 Variable rate due 2042	Dec. 31, 2012 Thereafter	Dec. 31, 2011 Thereafter	Dec. 31, 2012 Redeemable Preferred Stock, $1 par value Cumulative Preferred Stock	Dec. 31, 2011 Redeemable Preferred Stock, $1 par value Cumulative Preferred Stock	Dec. 31, 2012 Redeemable Preferred Stock, $100 par or stated value Cumulative Preferred Stock	Dec. 31, 2011 Redeemable Preferred Stock, $100 par or stated value Cumulative Preferred Stock	Dec. 31, 2012 Preference Stock , $100 par or stated value	Dec. 31, 2011 Preference Stock , $100 par or stated value	Dec. 31, 2012 Preference Stock, $1 par value	Dec. 31, 2011 Preference Stock, $1 par value	Dec. 31, 2012 Noncumulative Preferred Stock	Dec. 31, 2011 Noncumulative Preferred Stock	Dec. 31, 2012 Alabama Power [Member]	Dec. 31, 2011 Alabama Power [Member]	Dec. 31, 2012 Alabama Power [Member] Maturity of Pollution Control Bonds Two Thousand Thirty Four [Member]	Dec. 31, 2011 Alabama Power [Member] Maturity of Pollution Control Bonds Two Thousand Thirty Four [Member]	Dec. 31, 2012 Alabama Power [Member] Variable rate, Due 2015	Dec. 31, 2011 Alabama Power [Member] Variable rate, Due 2015	Dec. 31, 2012 Alabama Power [Member] Maturity Of Pollution Control Bonds Variable Rate Due Two Thousand Seventeen [Member]	Dec. 31, 2011 Alabama Power [Member] Maturity Of Pollution Control Bonds Variable Rate Due Two Thousand Seventeen [Member]	Dec. 31, 2012 Alabama Power [Member] Maturity Of Pollution Control Bonds Variable Rate Two Thousand Twenty One To Two Thousand Thirty Eight [Member]	Dec. 31, 2011 Alabama Power [Member] Maturity Of Pollution Control Bonds Variable Rate Two Thousand Twenty One To Two Thousand Thirty Eight [Member]	Dec. 31, 2012 Alabama Power [Member] Redeemable Preferred Stock, $1 par value Cumulative Preferred Stock	Dec. 31, 2011 Alabama Power [Member] Redeemable Preferred Stock, $1 par value Cumulative Preferred Stock	Dec. 31, 2012 Alabama Power [Member] Redeemable Preferred Stock, $100 par or stated value Cumulative Preferred Stock	Dec. 31, 2011 Alabama Power [Member] Redeemable Preferred Stock, $100 par or stated value Cumulative Preferred Stock	Dec. 31, 2012 Georgia Power [Member]	Dec. 31, 2011 Georgia Power [Member]	Dec. 31, 2012 Georgia Power [Member] 2022 - 2049	Dec. 31, 2011 Georgia Power [Member] 2022 - 2049	Dec. 31, 2012 Georgia Power [Member] Variable rate, Due 2016	Dec. 31, 2011 Georgia Power [Member] Variable rate, Due 2016	Dec. 31, 2012 Georgia Power [Member] Maturity of Pollution Control Bonds Variable Rate Due Two Thousand Eighteen to Two Thousand Fifty Two [Member]	Dec. 31, 2011 Georgia Power [Member] Maturity of Pollution Control Bonds Variable Rate Due Two Thousand Eighteen to Two Thousand Fifty Two [Member]	Dec. 31, 2012 Georgia Power [Member] Noncumulative Preferred Stock	Dec. 31, 2011 Georgia Power [Member] Noncumulative Preferred Stock	Dec. 31, 2012 Georgia Power [Member] Noncumulative Preferred Stock, $25 par value	Dec. 31, 2011 Georgia Power [Member] Noncumulative Preferred Stock, $25 par value	Dec. 31, 2012 Georgia Power [Member] Noncumulative Preferred Stock, $100 par value	Dec. 31, 2011 Georgia Power [Member] Noncumulative Preferred Stock, $100 par value	Dec. 31, 2012 Gulf Power [Member]	Dec. 31, 2011 Gulf Power [Member]	Dec. 31, 2012 Gulf Power [Member] 2022 - 2049	Dec. 31, 2011 Gulf Power [Member] 2022 - 2049	Dec. 31, 2012 Gulf Power [Member] Variable Rate, Due 2022-2039	Dec. 31, 2011 Gulf Power [Member] Variable Rate, Due 2022-2039	Dec. 31, 2012 Gulf Power [Member] 6% Preference stock	Dec. 31, 2011 Gulf Power [Member] 6% Preference stock	Dec. 31, 2012 Gulf Power [Member] 6.45 % Preference stock	Dec. 31, 2011 Gulf Power [Member] 6.45 % Preference stock	Dec. 31, 2012 Mississippi Power [Member]	Dec. 31, 2011 Mississippi Power [Member]	Dec. 31, 2012 Mississippi Power [Member] Variable Rate, Due 2020-2028	Dec. 31, 2011 Mississippi Power [Member] Variable Rate, Due 2020-2028	Dec. 31, 2012 Mississippi Power [Member] 2028	Dec. 31, 2011 Mississippi Power [Member] 2028	Dec. 31, 2012 Mississippi Power [Member] Thereafter	Dec. 31, 2011 Mississippi Power [Member] Thereafter	Dec. 31, 2012 Adjustable Rate Loans [Member]	Dec. 31, 2011 Adjustable Rate Loans [Member]
Maturity
Total long term debt payable to affiliated trusts	$ 206,000,000	$ 206,000,000											$ 206,000,000	$ 206,000,000													$ 206,000,000	$ 206,000,000
Fixed stated interest rate of debt obligation							0.17%				0.13%		3.41%		7.13%	7.13%															0.13%										7.90%	7.40%			0.17%																				9.967%						7.13%	7.13%
Long-term senior notes and debt:
Long-term debt maturities, 2016	1,360,000,000	1,210,000,000																									200,000,000	200,000,000													250,000,000	250,000,000													110,000,000	110,000,000									300,000,000	150,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,095,000,000	1,095,000,000																									525,000,000	525,000,000													450,000,000	450,000,000													85,000,000	85,000,000									35,000,000	35,000,000
Long-term debt maturities, thereafter	10,073,000,000	8,702,000,000																									3,450,000,000	3,300,000,000													4,425,000,000	3,575,000,000													615,000,000	606,363,000									805,000,000	445,000,000
Long Term Debt Maturities Repayments of Principal Adjustable in Last Twelve Months																																																																	0	240,000,000
Variable, 2011																																									0	250,000,000
Variable, 2012																																									650,000,000	650,000,000
Adjustable, 2013																																																																	226,471,000	0
2012	0	1,203,000,000																									0	500,000,000													0	200,000,000																															0	490,000,000
2013	1,436,000,000	1,436,000,000																									250,000,000	250,000,000													1,025,000,000	1,025,000,000													60,000,000	60,000,000									50,000,000	50,000,000							876,000,000	650,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	434,000,000	437,000,000																									0																												75,000,000	75,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	2,375,000,000	1,175,000,000																									400,000,000	0													1,050,000,000	250,000,000
Total long-term notes payable																											4,825,000,000	4,775,000,000													7,850,000,000	6,650,000,000													945,000,000	936,363,000									1,416,471,000	920,000,000
Total long -term senior notes and debt	17,649,000,000	16,398,000,000
Pollution control revenue bonds --
Long-term pollution control bonds			1,664,000,000	1,667,000,000	1,593,000,000	1,590,000,000	4,000,000	4,000,000	36,000,000	36,000,000	54,000,000	54,000,000															1,200,000,000		367,000,000	367,000,000	54,000,000	54,000,000	36,000,000	36,000,000	694,000,000	694,000,000					1,800,000,000	1,800,000,000	919,000,000	916,000,000	4,000,000	4,000,000	861,000,000	864,000,000							309,000,000	309,000,000	239,625,000	239,625,000	69,330,000	69,330,000					82,700,000	82,700,000	40,070,000	40,070,000	42,625,000	42,625,000
Taxable Revenue Bonds															270,000,000	270,000,000																																																	51,500,000						270,000,000	270,000,000
Total other long -term debt	3,621,000,000	3,621,000,000																									1,151,000,000	1,151,000,000													1,784,000,000	1,784,000,000													308,955,000	308,955,000									352,695,000	352,695,000
Capitalized lease obligations	80,000,000	93,000,000																																							50,000,000	55,000,000																							0	633,000
Unamortized debt (discount), net																											(3,000,000)	0													(10,000,000)	(16,000,000)													(8,085,000)	(9,871,000)
Unamortized debt premium (related to plant acquisition)	88,000,000	78,000,000																																																															80,912,000	74,551,000
Unamortized debt discount	(35,000,000)	(32,000,000)																																																															(9,145,000)	(3,650,000)
Total long-term debt (annual interest requirement )	21,609,000,000	20,364,000,000																									6,179,000,000	6,132,000,000													9,674,000,000	8,473,000,000													1,245,870,000	1,235,447,000									1,840,933,000	1,344,229,000
Less amount due within one year	2,335,000,000	1,717,000,000																									250,000,000	500,000,000													1,680,000,000	455,000,000													60,000,000	0									276,471,000	240,633,000
Long-term debt excluding amount due within one year	19,274,000,000	18,647,000,000																									5,929,000,000	5,632,000,000													7,994,000,000	8,018,000,000													1,185,870,000	1,235,447,000									1,564,462,000	1,103,596,000
Percent capitalization	49.90%	50.00%																									49.40%	48.40%													45.60%	46.40%													48.10%	50.20%									46.10%	50.50%
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	375,000,000	375,000,000															294,000,000	294,000,000	81,000,000	81,000,000							342,000,000	342,000,000									294,000,000	294,000,000	48,000,000	48,000,000
Total redeemable preferred stock - percent capitalization	1.00%	1.00%																									2.80%	2.90%																											4.00%	4.00%									1.00%	1.50%
Preference stock																											343,000,000	343,000,000													221,000,000	221,000,000											221,000,000	221,000,000	97,998,000	97,998,000					53,886,000	53,886,000	44,112,000	44,112,000
Preferred stock																											342,000,000	342,000,000													45,000,000	45,000,000									45,000,000	45,000,000													32,780,000	32,780,000
Preferred and preference stock of subsidiaries	707,000,000	707,000,000																			319,000,000	319,000,000	343,000,000	343,000,000	45,000,000	45,000,000
Total preferred and preference stock																																																	266,000,000	266,000,000
Total preferred and preference stock of subsidiaries - percent capitalization	1.80%	1.90%																									2.90%	2.90%													1.50%	1.50%
Common Stockholders' Equity:
Common stock	4,389,000,000	4,328,000,000																									1,222,000,000	1,222,000,000													398,000,000	398,000,000													393,060,000	353,060,000									37,691,000	37,691,000
Paid-in capital	4,855,000,000	4,410,000,000																									2,227,000,000	2,182,000,000													5,585,000,000	5,522,000,000													547,798,000	542,709,000									1,401,520,000	694,855,000
Treasury, at cost	(450,000,000)	(17,000,000)
Retained earnings	9,626,000,000	8,968,000,000																									1,976,000,000	1,956,000,000													3,297,000,000	3,112,000,000													241,465,000	231,333,000									366,875,000	325,568,000
Accumulated other comprehensive loss	(123,000,000)	(111,000,000)																									(27,000,000)	(18,000,000)													(7,000,000)	(9,000,000)													(1,581,000)	(2,154,000)									(8,713,000)	(8,897,000)
Total Common Stockholders' Equity	18,297,000,000	17,578,000,000																									5,398,000,000	5,342,000,000													9,273,000,000	9,023,000,000													1,180,742,000	1,124,948,000									1,797,373,000	1,049,217,000
Total common stockholders' equity - percent capitalization	47.30%	47.10%																									44.90%	45.80%													52.90%	52.10%													47.90%	45.80%									52.90%	48.00%
Total stockholders' equity	19,004,000,000	18,285,000,000																									5,398,000,000	5,342,000,000													9,273,000,000	9,023,000,000													1,180,742,000	1,124,948,000									1,797,373,000	1,049,217,000
Total Capitalization	$ 38,653,000,000	$ 37,307,000,000																									$ 12,012,000,000	$ 11,659,000,000													$ 17,533,000,000	$ 17,307,000,000													$ 2,464,610,000	$ 2,458,393,000									$ 3,394,615,000	$ 2,185,593,000
Percent Capitalization	100.00%	100.00%																									100.00%	100.00%													100.00%	100.00%													100.00%	100.00%									100.00%	100.00%