Financing (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Credit arrangements by company
Expires, 2012	$ 98
Expires, 2013	306
Expires, 2014 and Beyond	4,760
Total	5,164
Unused	5,159
Executable Term-Loans, One Year	146
Executable Term-Loans, Two Years	41
Due Within One Year, Term Out	187
Due Within One Year, No Term Out	157
Southern Company [Member]
Credit arrangements by company
Expires, 2014 and Beyond	1,000
Total	1,000
Unused	1,000
Alabama Power [Member]
Credit arrangements by company
Expires, 2012	37
Expires, 2013	101
Expires, 2014 and Beyond	1,150
Total	1,288
Unused	1,288
Executable Term-Loans, One Year	51
Due Within One Year, Term Out	51
Due Within One Year, No Term Out	52
Georgia Power [Member]
Credit arrangements by company
Expires, 2014 and Beyond	1,750
Total	1,750
Unused	1,745
Gulf Power [Member]
Credit arrangements by company
Expires, 2012	20
Expires, 2013	60
Expires, 2014 and Beyond	195
Total	275
Unused	275
Executable Term-Loans, One Year	45
Due Within One Year, Term Out	45
Due Within One Year, No Term Out	35
Mississippi Power [Member]
Credit arrangements by company
Expires, 2012	41
Expires, 2013	95
Expires, 2014 and Beyond	165
Total	301
Unused	301
Executable Term-Loans, One Year	25
Executable Term-Loans, Two Years	41
Due Within One Year, Term Out	66
Due Within One Year, No Term Out	70
Southern Power [Member]
Credit arrangements by company
Expires, 2014 and Beyond	500
Total	500
Unused	500
Other Subsidiaries [Member]
Credit arrangements by company
Expires, 2013	50
Total	50
Unused	50
Executable Term-Loans, One Year	25
Due Within One Year, Term Out	$ 25