Financing (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Credit arrangements by company
Expires, 2012	$ 352
Expires, 2013	60
Expires, 2014	930
Expires, 2016	3,800
Total	5,142
Unused	5,137
Due Within One Year, Term Out	217
Due Within One Year, No Term Out	136
Executable Term-Loans, One Year	176
Executable Term-Loans, Two Years	41
Southern Company [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	0
Expires, 2014	0
Expires, 2016	1,000
Total	1,000
Unused	1,000
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	0
Executable Term-Loans, One Year	0
Executable Term-Loans, Two Years	0
Alabama Power [Member]
Credit arrangements by company
Expires, 2012	121
Expires, 2013	35
Expires, 2014	350
Expires, 2016	800
Total	1,306
Unused	1,306
Due Within One Year, Term Out	51
Due Within One Year, No Term Out	71
Executable Term-Loans, One Year	51
Executable Term-Loans, Two Years	0
Georgia Power [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	0
Expires, 2014	250
Expires, 2016	1,500
Total	1,750
Unused	1,745
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	0
Executable Term-Loans, One Year	0
Executable Term-Loans, Two Years	0
Gulf Power [Member]
Credit arrangements by company
Expires, 2012	75
Expires, 2013	0
Expires, 2014	165
Expires, 2016	0
Total	240
Unused	240
Due Within One Year, Term Out	75
Due Within One Year, No Term Out	0
Executable Term-Loans, One Year	75
Executable Term-Loans, Two Years	0
Mississippi Power [Member]
Credit arrangements by company
Expires, 2012	131
Expires, 2013	0
Expires, 2014	165
Expires, 2016	0
Total	296
Unused	296
Due Within One Year, Term Out	66
Due Within One Year, No Term Out	65
Executable Term-Loans, One Year	25
Executable Term-Loans, Two Years	41
Southern Power [Member]
Credit arrangements by company
Expires, 2012	0
Expires, 2013	0
Expires, 2014	0
Expires, 2016	500
Total	500
Unused	500
Due Within One Year, Term Out	0
Due Within One Year, No Term Out	0
Executable Term-Loans, One Year	0
Executable Term-Loans, Two Years	0
Other Subsidiaries [Member]
Credit arrangements by company
Expires, 2012	25
Expires, 2013	25
Expires, 2014	0
Expires, 2016	0
Total	50
Unused	50
Due Within One Year, Term Out	25
Due Within One Year, No Term Out	0
Executable Term-Loans, One Year	25
Executable Term-Loans, Two Years	$ 0