Financing (Details) (USD $)	Jun. 30, 2013		Jun. 30, 2013 Southern Company [Member]		Jun. 30, 2013 Alabama Power [Member]		Jun. 30, 2013 Georgia Power [Member]		Jun. 30, 2013 Gulf Power [Member]		Jun. 30, 2013 Mississippi Power [Member]		Jun. 30, 2013 Southern Power [Member]		Jun. 30, 2013 Other Subsidiaries [Member]		Aug. 06, 2013 Subsequent Event [Member] SEGCO [Member]	Aug. 06, 2013 Maturity Of Credit Arrangement Year One [Member] Subsequent Event [Member] Alabama Power [Member]	Aug. 06, 2013 Maturity Of Credit Facility Year Two [Member] Subsequent Event [Member] Alabama Power [Member]
Credit arrangements by company
Expires, 2013	$ 162,000,000	[1]	$ 0	[1]	$ 77,000,000	[1]	$ 0	[1]	$ 20,000,000	[1]	$ 40,000,000	[1]	$ 0	[1]	$ 25,000,000	[1]
Expires, 2014	485,000,000	[1]	0	[1]	225,000,000	[1]	0	[1]	90,000,000	[1]	95,000,000	[1]	0	[1]	75,000,000	[1]
Expires, 2016	480,000,000	[1]	0	[1]	0	[1]	150,000,000	[1]	165,000,000	[1]	165,000,000	[1]	0	[1]	0	[1]
Expires, 2018	4,100,000,000	[1]	1,000,000,000	[1]	1,000,000,000	[1]	1,600,000,000	[1]	0	[1]	0	[1]	500,000,000	[1]	0	[1]
Total	5,227,000,000		1,000,000,000		1,302,000,000		1,750,000,000		275,000,000		300,000,000		500,000,000		100,000,000
Unused	5,202,000,000		1,000,000,000		1,301,000,000		1,740,000,000		275,000,000		300,000,000		486,000,000		100,000,000
Executable Term-Loans, One Year	148,000,000		0		53,000,000		0		45,000,000		25,000,000		0		25,000,000
Executable Term-Loans, Two Years	40,000,000		0		0		0		0		40,000,000		0		0
Due Within One Year, Term Out	188,000,000		0		53,000,000		0		45,000,000		65,000,000		0		25,000,000
Due Within One Year, No Term Out	309,000,000		0		99,000,000		0		65,000,000		70,000,000		0		75,000,000
Line of Credit Facility, Amount Outstanding																	$ 25,000,000	$ 10,000,000	$ 35,000,000

[1] No credit arrangements expire in 2015 or 2017.