Derivatives (Details 1) (USD $) In Millions	Sep. 30, 2011
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	$ 183
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	12
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	12
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Georgia Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	3
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	15
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	17
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	3
Mississippi Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	2
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Southern Power [Member] | Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Cash Flow and Fair Value Hedging [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	19
Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	6
Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	10
Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	15
Cash Flow and Fair Value Hedging [Member] | Interest rate derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	12
Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	29
Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	3
Cash Flow and Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	2
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Liability Derivatives	29
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	24
Alabama Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	5
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	2
Liability Derivatives	68
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	53
Georgia Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	15
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Liability Derivatives	17
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	10
Gulf Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	7
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Liability Derivatives	35
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	27
Mississippi Power [Member] | Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	8
Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	2
Liability Derivatives	149
Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred charges and assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	114
Hedging Instruments for Regulatory Purposes [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	35
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Assets from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Alabama Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Georgia Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Georgia Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Georgia Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Assets from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Gulf Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Assets from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Mississippi Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	0
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Assets from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Southern Power [Member] | Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	5
Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Other current assets [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Assets from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Not Designated as Hedging Instrument [Member] | Energy-related derivatives [Member] | Liabilities from risk management activities [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	5
Alabama Power [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	41
Alabama Power [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(29)
Alabama Power [Member] | Energy-related derivatives [Member] | Other Current Liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Alabama Power [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Alabama Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(24)
Alabama Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(5)
Alabama Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Alabama Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Georgia Power [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	68
Georgia Power [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	2
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(66)
Georgia Power [Member] | Energy-related derivatives [Member] | Other Current Liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	1
Georgia Power [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	1
Georgia Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(53)
Georgia Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(15)
Georgia Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Georgia Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Gulf Power [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	17
Gulf Power [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	0
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(17)
Gulf Power [Member] | Energy-related derivatives [Member] | Other Current Liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Gulf Power [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Gulf Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(10)
Gulf Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(7)
Gulf Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Gulf Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Mississippi Power [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	52
Mississippi Power [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	3
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(35)
Mississippi Power [Member] | Energy-related derivatives [Member] | Other Current Liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Mississippi Power [Member] | Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Mississippi Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(27)
Mississippi Power [Member] | Energy-related derivatives [Member] | Other regulatory assets, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(8)
Mississippi Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Mississippi Power [Member] | Energy-related derivatives [Member] | Other regulatory liabilities, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Southern Power [Member]
Fair value of energy-related derivatives and interest rate derivatives
Liability Derivatives	5
Southern Power [Member] | Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	1
Energy-related derivatives [Member]
Fair value of energy-related derivatives and interest rate derivatives
Asset Derivatives	22
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(147)
Energy-related derivatives [Member] | Other Current Liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Energy-related derivatives [Member] | Other deferred credits and liabilities [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	0
Energy-related derivatives [Member] | Other regulatory assets, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(114)
Energy-related derivatives [Member] | Other regulatory assets, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	(35)
Energy-related derivatives [Member] | Other regulatory liabilities, current [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	1
Energy-related derivatives [Member] | Other regulatory liabilities, deferred [Member]
Pre-tax effect of unrealized derivative gains (losses)
Regulatory hedge unrealized gain (loss) recognized on balance sheet	$ 1