Financing (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
Credit arrangements by company
Expires, 2012	$ 36
Expires, 2013	387
Expires, 2014 and Beyond	4,760	[1]
Total	5,183
Unused	5,173
Executable Term-Loans, One Year	150
Executable Term-Loans, Two Years	41
Due Within One Year, Term Out	191	[2]
Due Within One Year, No Term Out	232	[2]
Southern Company [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	0
Expires, 2014 and Beyond	1,000	[1]
Total	1,000
Unused	1,000
Executable Term-Loans, One Year	0
Executable Term-Loans, Two Years	0
Due Within One Year, Term Out	0	[2]
Due Within One Year, No Term Out	0	[2]
Alabama Power [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	157
Expires, 2014 and Beyond	1,150	[1]
Total	1,307
Unused	1,307
Executable Term-Loans, One Year	55
Executable Term-Loans, Two Years	0
Due Within One Year, Term Out	55	[2]
Due Within One Year, No Term Out	102	[2]
Georgia Power [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	0
Expires, 2014 and Beyond	1,750	[1]
Total	1,750
Unused	1,740
Executable Term-Loans, One Year	0
Executable Term-Loans, Two Years	0
Due Within One Year, Term Out	0	[2]
Due Within One Year, No Term Out	0	[2]
Gulf Power [Member]
Credit arrangements by company
Expires, 2012	20
Expires, 2013	60
Expires, 2014 and Beyond	195	[1]
Total	275
Unused	275
Executable Term-Loans, One Year	45
Executable Term-Loans, Two Years	0
Due Within One Year, Term Out	45	[2]
Due Within One Year, No Term Out	35	[2]
Mississippi Power [Member]
Credit arrangements by company
Expires, 2012	16
Expires, 2013	120
Expires, 2014 and Beyond	165	[1]
Total	301
Unused	301
Executable Term-Loans, One Year	25
Executable Term-Loans, Two Years	41
Due Within One Year, Term Out	66	[2]
Due Within One Year, No Term Out	70	[2]
Southern Power [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	0
Expires, 2014 and Beyond	500	[1]
Total	500
Unused	500
Executable Term-Loans, One Year	0
Executable Term-Loans, Two Years	0
Due Within One Year, Term Out	0	[2]
Due Within One Year, No Term Out	0	[2]
Other Subsidiaries [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	50
Expires, 2014 and Beyond	0	[1]
Total	50
Unused	50
Executable Term-Loans, One Year	25
Executable Term-Loans, Two Years	0
Due Within One Year, Term Out	25	[2]
Due Within One Year, No Term Out	$ 25	[2]

[1] All remaining Gulf Power and Mississippi Power credit agreements in this column expire in 2014.

[2] Reflects facilities expiring on or before September 30, 2013.