Segment and Related Information (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Financial data for business segments
Operating revenues	$ 3,696,000,000	$ 5,428,000,000	$ 4,521,000,000	$ 4,012,000,000	$ 3,771,000,000	$ 5,320,000,000	$ 4,208,000,000	$ 4,157,000,000	$ 17,657,000,000	$ 17,456,000,000	$ 15,743,000,000
Depreciation and amortization									1,717,000,000	1,513,000,000	1,503,000,000
Interest income									21,000,000	24,000,000	23,000,000
Interest expense									857,000,000	895,000,000	905,000,000
Income taxes									1,219,000,000	1,026,000,000	896,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries	261,000,000	916,000,000	604,000,000	422,000,000	153,000,000	817,000,000	510,000,000	495,000,000	2,203,000,000	1,975,000,000	1,643,000,000
Total Assets	59,267,000,000				55,032,000,000				59,267,000,000	55,032,000,000	52,046,000,000
Gross property additions									4,853,000,000	4,443,000,000	4,913,000,000
Electric Utilities [Member]
Financial data for business segments
Operating revenues									17,587,000,000	17,374,000,000	15,642,000,000
Depreciation and amortization									1,700,000,000	1,495,000,000	1,476,000,000
Interest income									19,000,000	22,000,000	21,000,000
Interest expense									803,000,000	833,000,000	834,000,000
Income taxes									1,293,000,000	1,114,000,000	988,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries									2,214,000,000	1,991,000,000	1,835,000,000
Total Assets	58,076,000,000				54,454,000,000				58,076,000,000	54,454,000,000	51,303,000,000
Gross property additions									4,844,000,000	4,434,000,000	4,899,000,000
Traditional Operating Companies [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues									16,763,000,000	16,712,000,000	15,304,000,000
Depreciation and amortization									1,576,000,000	1,376,000,000	1,378,000,000
Interest income									18,000,000	22,000,000	21,000,000
Interest expense									726,000,000	757,000,000	749,000,000
Income taxes									1,217,000,000	1,039,000,000	902,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries									2,052,000,000	1,860,000,000	1,679,000,000
Total Assets	54,622,000,000				51,144,000,000				54,622,000,000	51,144,000,000	48,403,000,000
Gross property additions									4,589,000,000	4,029,000,000	4,568,000,000
Southern Power [Member]
Segment and Related Information (Textual) [Abstract]
Southern Power's revenues from sales to the traditional operating companies									359,000,000	371,000,000	544,000,000
Southern Power [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues									1,236,000,000	1,130,000,000	947,000,000
Depreciation and amortization									124,000,000	119,000,000	98,000,000
Interest income									1,000,000
Interest expense									77,000,000	76,000,000	85,000,000
Income taxes									76,000,000	75,000,000	86,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries									162,000,000	131,000,000	156,000,000
Total Assets	3,581,000,000				3,438,000,000				3,581,000,000	3,438,000,000	3,043,000,000
Gross property additions									255,000,000	405,000,000	331,000,000
Eliminations [Member]
Financial data for business segments
Depreciation and amortization									1,000,000
Eliminations [Member] | Electric Utilities [Member]
Financial data for business segments
Operating revenues									(412,000,000)	(468,000,000)	(609,000,000)
Total Assets	(127,000,000)				(128,000,000)				(127,000,000)	(128,000,000)	(143,000,000)
All Other [Member]
Financial data for business segments
Operating revenues									149,000,000	162,000,000	165,000,000
Depreciation and amortization									16,000,000	18,000,000	27,000,000
Interest income									3,000,000	3,000,000	3,000,000
Interest expense									54,000,000	63,000,000	71,000,000
Income taxes									(74,000,000)	(89,000,000)	(92,000,000)
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries									(8,000,000)	(11,000,000)	(193,000,000)
Total Assets	1,592,000,000				1,178,000,000				1,592,000,000	1,178,000,000	1,223,000,000
Gross property additions									9,000,000	9,000,000	14,000,000
Eliminations [Member]
Financial data for business segments
Operating revenues									(79,000,000)	(80,000,000)	(64,000,000)
Interest income									(1,000,000)	(1,000,000)	(1,000,000)
Interest expense										(1,000,000)
Income taxes										1,000,000
Consolidated Net Income After Dividends on Preferred and Preference Stock of Subsidiaries									(3,000,000)	(5,000,000)	1,000,000
Total Assets	$ (401,000,000)				$ (600,000,000)				$ (401,000,000)	$ (600,000,000)	$ (480,000,000)