Derivatives - Schedule of Derivatives and Gains (Losses) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Alabama Power [Member]
Notional amount of interest rate derivatives
Notional Amount	$ 75
Fair Value Hedging [Member] | Alabama Power [Member]
Notional amount of interest rate derivatives
Interest Rate Received	3-month LIBOR
Weighted Average Interest Rate Paid	3.12108%
Hedge Maturity Date	Oct. 01, 2025
Fair Value Gain (Loss) June 30, 2014	$ 0
Gas [Member] | Southern Company [Member]
Energy-related derivative contracts
Net Purchased mmBtu	250,000,000
Longest Hedge Date	2018
Longest Non-hedge Date	2017
Gas [Member] | Alabama Power [Member]
Energy-related derivative contracts
Net Purchased mmBtu	63,000,000
Longest Hedge Date	2017
Gas [Member] | Georgia Power [Member]
Energy-related derivative contracts
Net Purchased mmBtu	50,000,000
Longest Hedge Date	2017
Gas [Member] | Gulf Power [Member]
Energy-related derivative contracts
Net Purchased mmBtu	85,000,000
Longest Hedge Date	2018
Gas [Member] | Mississippi Power [Member]
Energy-related derivative contracts
Net Purchased mmBtu	51,000,000
Longest Hedge Date	2017
Gas [Member] | Southern Power [Member]
Energy-related derivative contracts
Net Purchased mmBtu	1,000,000
Longest Non-hedge Date	2017