Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Common stock, par value per share	5	5
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	878,000,000	866,000,000
Alabama Power [Member]
Common stock, par value per share	40	40
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares outstanding	30,537,500	30,537,500
Georgia Power [Member]
Fixed stated interest rate of debt obligation	7.90%	7.40%
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares outstanding	9,261,500	9,261,500
Gulf Power [Member]
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares outstanding	4,542,717	4,142,717
Mississippi Power [Member]
Fixed stated interest rate of debt obligation	9.967%
Common stock, shares authorized	1,130,000	1,130,000
Common stock, shares outstanding	1,121,000	1,121,000
Southern Power [Member]
Amortization expense on other intangible assets	3,141	1,476
Common stock, par value per share	0.01	0.01
Common stock, shares authorized	1,000,000	1,000,000
Common stock, shares outstanding	1,000	1,000
Southern Power [Member] | 4.875% due 2015
Fixed stated interest rate of debt obligation	4.875%	4.875%
Southern Power [Member] | 6.375% due 2036
Fixed stated interest rate of debt obligation	6.375%	6.375%
Southern Power [Member] | 5.15% due 2041
Fixed stated interest rate of debt obligation	5.15%	5.15%
Southern Power [Member] | 3.25% due 2032
Fixed stated interest rate of debt obligation	3.25%	3.25%