Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Southern Company [Member]
Changes in fair value, tax	$ (11)	$ 0	$ (10)	$ 0
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	1	1	3	2
Reclassification adjustment for amounts of pension and other post retirement benefit plans included in net income, tax	1	1	3	2
Alabama Power [Member]
Changes in fair value, tax	(4)	0	(4)	0
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	0	1	1	1
Georgia Power [Member]
Changes in fair value, tax	(7)	0	(7)	0
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	0	1	1	1
Mississippi Power [Member]
Reclassification adjustment for amounts of qualifying hedges included in net income, tax	$ 0	$ 0	$ 0	$ 0