Segment and Related Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Financial data for business segments
Operating revenues	$ 5,428,000,000	$ 5,320,000,000	$ 13,961,000,000	$ 13,685,000,000
Segment net income (loss)	916,000,000	817,000,000	1,942,000,000	1,822,000,000
Total Assets	57,343,000,000		57,343,000,000		55,032,000,000
Traditional Operating Companies [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues	5,145,000,000	5,066,000,000	13,246,000,000	13,127,000,000
Segment net income (loss)	862,000,000	756,000,000	1,805,000,000	1,713,000,000
Total Assets	52,949,000,000		52,949,000,000		51,144,000,000
Southern Power [Member]
Segment and Related Information (Textual) [Abstract]
Southern Power's revenues from sales to the traditional operating companies	85,000,000	93,000,000	239,000,000	288,000,000
Southern Power [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues	363,000,000	357,000,000	950,000,000	862,000,000
Segment net income (loss)	56,000,000	63,000,000	138,000,000	109,000,000
Total Assets	3,757,000,000		3,757,000,000		3,438,000,000
Eliminations [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues	(97,000,000)	(124,000,000)	(288,000,000)	(367,000,000)
Total Assets	(160,000,000)		(160,000,000)		(128,000,000)
All Other Segments [Member]
Financial data for business segments
Operating revenues	38,000,000	40,000,000	114,000,000	122,000,000
Segment net income (loss)		(1,000,000)	2,000,000	2,000,000
Total Assets	1,431,000,000		1,431,000,000		1,178,000,000
Eliminations [Member]
Financial data for business segments
Operating revenues	(21,000,000)	(19,000,000)	(61,000,000)	(59,000,000)
Segment net income (loss)	(2,000,000)	(1,000,000)	(3,000,000)	(2,000,000)
Total Assets	(634,000,000)		(634,000,000)		(600,000,000)
Electric Utilities [Member]
Financial data for business segments
Operating revenues	5,411,000,000	5,299,000,000	13,908,000,000	13,622,000,000
Segment net income (loss)	918,000,000	819,000,000	1,943,000,000	1,822,000,000
Total Assets	$ 56,546,000,000		$ 56,546,000,000		$ 54,454,000,000