Segment and Related Information (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011
Financial data for business segments
Operating revenues	$ 5,049,000,000		$ 5,428,000,000		$ 12,834,000,000		$ 13,961,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	976,000,000	[1]	916,000,000	[1]	1,967,000,000	[1]	1,942,000,000	[1]
Total Assets	61,963,000,000				61,963,000,000				59,267,000,000
Electric Utilities [Member]
Financial data for business segments
Operating revenues	5,033,000,000		5,411,000,000		12,788,000,000		13,908,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	977,000,000	[1]	918,000,000	[1]	1,941,000,000	[1]	1,943,000,000	[1]
Total Assets	61,486,000,000				61,486,000,000				58,076,000,000
Traditional Operating Companies [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues	4,794,000,000		5,145,000,000		12,232,000,000		13,246,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	908,000,000	[1]	862,000,000	[1]	1,797,000,000	[1]	1,805,000,000	[1]
Total Assets	57,862,000,000				57,862,000,000				54,622,000,000
Southern Power [Member]
Segment and Related Information (Textual) [Abstract]
Southern Power's revenues from sales to the traditional operating companies	112,000,000		85,000,000		330,000,000		239,000,000
Southern Power [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues	355,000,000		363,000,000		894,000,000		950,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	68,000,000	[1]	56,000,000	[1]	144,000,000	[1]	138,000,000	[1]
Total Assets	3,782,000,000				3,782,000,000				3,581,000,000
Eliminations [Member]
Financial data for business segments
Operating revenues	(20,000,000)		(21,000,000)		(63,000,000)		(61,000,000)
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	(2,000,000)	[1]	(2,000,000)	[1]	(4,000,000)	[1]	(3,000,000)	[1]
Total Assets	(607,000,000)				(607,000,000)				(401,000,000)
Eliminations [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues	(116,000,000)		(97,000,000)		(338,000,000)		(288,000,000)
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	1,000,000	[1]	0	[1]	0	[1]	0	[1]
Total Assets	(158,000,000)				(158,000,000)				(127,000,000)
All Other [Member]
Financial data for business segments
Operating revenues	36,000,000		38,000,000		109,000,000		114,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	1,000,000	[1]	0	[1]	30,000,000	[1]	2,000,000	[1]
Total Assets	$ 1,084,000,000				$ 1,084,000,000				$ 1,592,000,000

[1] After dividends on preferred and preference stock of subsidiaries