Financing (DetailsTextual) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2011
Line of Credit Facility [Line Items]
Credit Arrangements expiration period	2016
Financing Textual [Abstract]
Ratio of indebtedness to capitalization covenant	0.65
Southern Company [Member]
Line of Credit Facility [Line Items]
Credit Arrangements	$ 1,000
Alabama Power [Member]
Line of Credit Facility [Line Items]
Credit Arrangements	800
Alabama Power [Member] | Credit arrangements expire in 2014 [Member]
Line of Credit Facility [Line Items]
Credit Arrangements	30
Credit Arrangements expiration period	2014
Alabama Power [Member] | Existing credit arrangements expire in 2011 [Member]
Line of Credit Facility [Line Items]
Credit Arrangements	20
Credit Arrangements expiration period	2011
Georgia Power [Member]
Line of Credit Facility [Line Items]
Credit Arrangements	1,500
Southern Power [Member]
Line of Credit Facility [Line Items]
Credit Arrangements	$ 500