Derivatives - Textual (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 MMBTU		Dec. 31, 2012	Dec. 31, 2011
Derivatives (Textual) [Abstract]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints	9,000,000
Fair value of derivative liabilities with contingent features	$ 9,000,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	9,000,000
Alabama Power [Member]
Derivatives (Textual) [Abstract]
Net volume of energy-related derivative contracts for natural gas positions	69,000,000	[1]
Longest Hedge Date	2017
Estimated pre-tax losses that will be reclassified from OCI to interest expense for the next 12-month period	3,000,000
Fair value of derivative liabilities with contingent features	1,000,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	9,000,000
Georgia Power [Member]
Derivatives (Textual) [Abstract]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints	5,000,000
Date through which deferred gains and losses are expected to be amortized into earnings	2037
Fair value of derivative liabilities with contingent features	3,000,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	9,000,000
Gulf Power [Member]
Derivatives (Textual) [Abstract]
Net volume of energy-related derivative contracts for natural gas positions	88,620,000
Longest Hedge Date	2018
Estimated pre-tax losses that will be reclassified from OCI to interest expense for the next 12-month period	600,000
Fair value of derivative liabilities with contingent features	3,700,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	8,800,000
Mississippi Power [Member]
Derivatives (Textual) [Abstract]
Net volume of energy-related derivative contracts for natural gas positions	56,000,000	[2]
Longest Hedge Date	2017
Estimated pre-tax losses that will be reclassified from OCI to interest expense for the next 12-month period	1,400,000
Pre-tax losses from foreign currency derivatives designated as fair value hedging instruments including pre-tax losses associated with de-designated hedges prior to de-designation			600,000	3,600,000
Fair value of derivative liabilities with contingent features	1,500,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	8,800,000
Southern Power [Member]
Derivatives (Textual) [Abstract]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints	1,400,000
Realized gain on termination of interest rate derivatives	0		(200,000)	100,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	8,800,000
Interest rate hedges [Member] | Southern Power [Member]
Derivatives (Textual) [Abstract]
Estimated pre-tax losses that will be reclassified from OCI to interest expense for the next 12-month period	$ 900,000
Public Utilities, Inventory, Natural Gas [Member]
Derivatives (Textual) [Abstract]
Net volume of energy-related derivative contracts for natural gas positions	275,000,000
Public Utilities, Inventory, Natural Gas [Member] | Georgia Power [Member]
Derivatives (Textual) [Abstract]
Net volume of energy-related derivative contracts for natural gas positions	60,000,000
Longest Hedge Date	2017
Public Utilities, Inventory, Natural Gas [Member] | Southern Power [Member]
Derivatives (Textual) [Abstract]
Net volume of energy-related derivative contracts for natural gas positions	1,600,000
Longest Non-Hedge Date	2017
Public Utilities, Inventory, Fuel [Member]
Derivatives (Textual) [Abstract]
Longest Hedge Date	2018
Longest Non-Hedge Date	2017

[1] *million British thermal units (mmBtu)

[2] *mmBtu — million British thermal units