Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Changes in fair value of qualifying hedges, tax	$ 1,000,000	$ (10,000,000)	$ (4,000,000)	$ (8,000,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	1,000,000	2,000,000	4,000,000	4,000,000
Change in fair value of marketable securities, tax	0	(2,000,000)	0	(1,000,000)
Reclassification adjustment for amounts of pension and other post retirement benefit plans included in net income, tax	0	2,000,000	1,000,000	2,000,000
Alabama Power [Member]
Changes in fair value of qualifying hedges, tax	(2,000,000)	(4,000,000)	(6,000,000)	(3,000,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax		0		(1,000,000)
Georgia Power [Member]
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	0	0	1,000,000	1,000,000
Gulf Power [Member]
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	90,000	90,000	270,000	270,000
Mississippi Power [Member]
Changes in fair value of qualifying hedges, tax		(5,630,000)	(296,000)	(5,624,000)
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	131,000		279,000
Southern Power [Member]
Changes in fair value of qualifying hedges, tax	215,000	(135,000)	95,000	265,000
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	$ 999,000	$ 1,106,000	$ 2,911,000	$ 3,261,000