Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Changes in fair value of qualifying hedges, tax	$ (10,000,000)		$ (3,000,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	6,000,000	9,000,000	18,000,000
Change in fair value of marketable securities, tax	(2,000,000)	(2,000,000)	1,000,000
Benefit plan net gain (loss), tax	(1,000,000)	1,000,000	(8,000,000)
Reclassification adjustment for amounts of pension and other post retirement benefit plans included in net income, tax	(14,000,000)	1,000,000	1,000,000
Alabama Power [Member]
Changes in fair value of qualifying hedges, tax	(5,000,000)		(2,000,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	(1,000,000)	(1,000,000)	5,000,000
Georgia Power [Member]
Changes in fair value of qualifying hedges, tax			(1,000,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	2,000,000	6,000,000	9,000,000
Gulf Power [Member]
Changes in fair value of qualifying hedges, tax		(542,000)	1,132,000
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	360,000	376,000	419,000
Mississippi Power [Member]
Changes in fair value of qualifying hedges, tax	(5,494,000)	1,000
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	(18,000)
Southern Power [Member]
Changes in fair value of qualifying hedges, tax	55,000	591,000	(664,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	$ 4,837,000	$ 3,894,000	$ 3,875,000