Effective Tax Rate and Unrecognized Tax Benefits - Narrative (Details)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Effective Tax Rate and Unrecognized Tax Benefits (Textual) [Abstract]
Effective tax rate	24.50%	34.20%
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	12 months
Alabama Power [Member]
Effective Tax Rate and Unrecognized Tax Benefits (Textual) [Abstract]
Effective tax rate	39.20%	38.30%
Georgia Power [Member]
Effective Tax Rate and Unrecognized Tax Benefits (Textual) [Abstract]
Effective tax rate	38.10%	34.90%
Gulf Power [Member]
Effective Tax Rate and Unrecognized Tax Benefits (Textual) [Abstract]
Effective tax rate	37.60%	34.60%
Mississippi Power [Member]
Effective Tax Rate and Unrecognized Tax Benefits (Textual) [Abstract]
Effective tax rate	(40.80%)	24.70%
Southern Power [Member]
Effective Tax Rate and Unrecognized Tax Benefits (Textual) [Abstract]
Effective tax rate	33.50%	31.30%