Income Taxes - Textual (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jan. 02, 2013
Income Tax Disclosure [Line Items]
Net cash payments/(refunds) for income taxes	$ 139,000,000	$ 38,000,000	$ (401,000,000)
Net operating loss carryforward	707,000,000
State income tax benefits as a result of utilization of State of Georgia net operating loss carryforward	41,000,000
Deferred tax assets	3,624,000,000	3,972,000,000
Tax Credit Carryforward, Amount	28,000,000
State Investment Tax Credit	118,000,000
Tax regulatory assets	1,400,000,000
Tax regulatory liabilities	202,000,000
Amortization of deferred investment tax credits	16,000,000	23,000,000	19,000,000
Unamortized investment tax credits	966,000,000	894,000,000
Percentage of additional bonus depreciation for property acquired	100.00%
Percentage of extension bonus depreciation for property acquired	50.00%
Balance of unrecognized tax benefits	7,000,000	70,000,000	120,000,000	296,000,000
Alabama Power [Member]
Income Tax Disclosure [Line Items]
Net cash payments/(refunds) for income taxes	296,000,000	309,000,000	(139,000,000)
Deferred tax assets	938,000,000	1,040,000,000
Tax regulatory assets	519,000,000
Tax regulatory liabilities	75,000,000
Amortization of deferred investment tax credits	8,000,000	8,000,000	8,000,000
Unamortized investment tax credits	133,000,000	141,000,000
Percentage of additional bonus depreciation for property acquired	100.00%
Percentage of extension bonus depreciation for property acquired	50.00%
Balance of unrecognized tax benefits	0	31,000,000	32,000,000	43,000,000
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	12 months
Georgia Power [Member]
Income Tax Disclosure [Line Items]
Net cash payments/(refunds) for income taxes	298,000,000	312,000,000	54,000,000
Deferred tax assets	1,464,000,000	1,656,000,000
State Investment Tax Credit	27,000,000	36,000,000	53,000,000
Tax regulatory assets	722,000,000
Tax regulatory liabilities	112,000,000
Regulatory Liabilities			62,000,000
Amortization of deferred investment tax credits	5,000,000	13,000,000	9,000,000
Federal Tax Credits	3,000,000
State Investment Tax Credit Carryforward	118,000,000
Unamortized investment tax credits	203,000,000	208,000,000
Percentage of additional bonus depreciation for property acquired	100.00%
Percentage of extension bonus depreciation for property acquired	50.00%
Balance of unrecognized tax benefits	0	23,000,000	47,000,000	237,000,000
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	12 months
Gulf Power [Member]
Income Tax Disclosure [Line Items]
Net cash payments/(refunds) for income taxes	(10,727,000)	(96,639,000)	(26,345,000)
Deferred tax assets	133,006,000	157,901,000
Tax regulatory assets	50,900,000
Tax regulatory liabilities	5,200,000
Amortization of deferred investment tax credits	1,400,000	1,400,000	1,300,000
Unamortized investment tax credits	4,055,000	5,408,000
Percentage of additional bonus depreciation for property acquired	100.00%
Percentage of extension bonus depreciation for property acquired	50.00%
Balance of unrecognized tax benefits	45,000	5,007,000	2,892,000	3,870,000
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	12 months
Mississippi Power [Member]
Income Tax Disclosure [Line Items]
Net cash payments/(refunds) for income taxes	(134,198,000)	(77,580,000)	(41,024,000)
Deferred tax assets	673,467,000	449,671,000
Tax Credit Carryforward, Amount	276,400,000
Tax regulatory assets	144,400,000
Tax regulatory liabilities	10,200,000
Regulatory Liabilities	98,100,000
Amortization of deferred investment tax credits	1,200,000	1,200,000	1,300,000
Unamortized investment tax credits	284,248,000	370,554,000
Minimum Percentage of Carbon Dioxide That Must Capture and Sequester to Remain Eligible for Tax Credits	65.00%
Percentage of additional bonus depreciation for property acquired	100.00%
Percentage of extension bonus depreciation for property acquired	50.00%
Reduction in income tax expense, investment tax credits	(144,036,000)	(82,464,000)	0
Balance of unrecognized tax benefits	3,840,000	5,755,000	4,964,000	4,288,000
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	12 months
Mississippi Power [Member] | Kemper IGCC [Member]
Income Tax Disclosure [Line Items]
Unamortized investment tax credits	276,400,000
Mississippi Power [Member] | Investment tax credit carryforward [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets	0	170,938,000
Southern Power [Member]
Income Tax Disclosure [Line Items]
Net cash payments/(refunds) for income taxes	(226,179,000)	(175,269,000)	(26,486,000)
Deferred Tax Asset, Reimbursable	2,600,000
Net operating loss carryforward	240,800,000	117,700,000
Deferred tax assets	127,700,000	91,700,000
Increase (decrease) in deferred tax assets valuation allowance	18,600,000
Operating Loss Carryforwards In Year Three	87,000,000
Operating Loss Carryforwards In Year Four	40,000,000
Operating Loss Carryforwards In Year Five	107,000,000
Percentage of additional bonus depreciation for property acquired				100.00%
Percentage of extension bonus depreciation for property acquired	50.00%	50.00%
Reduction in income tax expense, investment tax credits	(158,096,000)	(45,047,000)	(84,723,000)
Balance of unrecognized tax benefits	1,500,000	2,900,000	2,600,000	2,300,000
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	12 months
Positive Impact From Bonus Depreciation					98,900,000
Southern Power [Member] | Accounts Payable - Affiliated Companies [Member]
Income Tax Disclosure [Line Items]
Deferred Tax Asset, Reimbursable	1,000,000
Southern Power [Member] | Georgia Power [Member]
Income Tax Disclosure [Line Items]
Deferred Tax Liability, Reimbursable	2,800,000
Southern Power [Member] | Georgia Power [Member] | Receivables - Affiliated Companies [Member]
Income Tax Disclosure [Line Items]
Deferred Tax Liability, Reimbursable	300,000
Southern Power [Member] | Operating Loss Carryforward [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets	11,000,000	5,400,000
Southern Power [Member] | Investment tax credit carryforward [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets	58,000,000	28,600,000
Southern Power [Member] | Investment tax credit carryforward [Member] | Nacogdoches Biomass Generating Plant [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforward	158,100,000	45,000,000	84,700,000	42,900,000
Reduction in income tax expense, investment tax credits	$ 31,300,000	$ 6,900,000	$ 7,300,000