Effective Tax Rate and Unrecognized Tax Benefits (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Changes for unrecognized tax benefits [Abstract]
Unrecognized tax benefits as of December 31, 2010	$ 296
Tax positions from current periods	43
Tax positions from prior periods	(67)
Reductions due to settlements	(112)
Reductions due to expired statute of limitations	0
Balance as of March 31, 2011	160		296
Impact on effective tax rate
Tax positions impacting the effective tax rate	73		217
Tax positions not impacting the effective tax rate	87		79
Balance of unrecognized tax benefits	160		296
Accrued interest for unrecognized tax benefits
Interest accrued as of December 31, 2010	29
Interest reclassified due to settlements	(24)
Interest accrued during the period	5
Balance as of March 31, 2011	10		29
Effective Tax Rate and Unrecognized Tax Benefits (Textuals) [Abstract]
Effective tax rate	35.40%	31.80%
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	Next 12 Months
Positive cash flow due to tax accounting method for repair costs			297
Alabama Power [Member]
Changes for unrecognized tax benefits [Abstract]
Unrecognized tax benefits as of December 31, 2010	43
Tax positions from current periods	4
Reductions due to expired statute of limitations	0
Balance as of March 31, 2011	47		43
Impact on effective tax rate
Balance of unrecognized tax benefits	47		43
Effective Tax Rate and Unrecognized Tax Benefits (Textuals) [Abstract]
Effective tax rate	38.50%	36.90%
Positive cash flow due to tax accounting method for repair costs			141
Georgia Power [Member]
Changes for unrecognized tax benefits [Abstract]
Unrecognized tax benefits as of December 31, 2010	237
Tax positions from current periods	7
Tax positions from prior periods	(67)
Reductions due to settlements	(112)
Reductions due to expired statute of limitations	0
Balance as of March 31, 2011	65		237
Impact on effective tax rate
Tax positions impacting the effective tax rate	26
Tax positions not impacting the effective tax rate	39
Balance of unrecognized tax benefits	65		237
Accrued interest for unrecognized tax benefits
Interest accrued as of December 31, 2010	27
Interest reclassified due to settlements	(24)
Interest accrued during the period	3
Balance as of March 31, 2011	6		27
Effective Tax Rate and Unrecognized Tax Benefits (Textuals) [Abstract]
Effective tax rate	34.80%	30.10%
Positive cash flow due to tax accounting method for repair costs			133
Gulf Power [Member]
Changes for unrecognized tax benefits [Abstract]
Unrecognized tax benefits as of December 31, 2010	4
Reductions due to expired statute of limitations	0
Balance as of March 31, 2011	4		4
Impact on effective tax rate
Balance of unrecognized tax benefits	4		4
Effective Tax Rate and Unrecognized Tax Benefits (Textuals) [Abstract]
Effective tax rate	35.90%	36.20%
Positive cash flow due to tax accounting method for repair costs			8
Mississippi Power [Member]
Changes for unrecognized tax benefits [Abstract]
Unrecognized tax benefits as of December 31, 2010	4
Tax positions from current periods	1
Reductions due to expired statute of limitations	0
Balance as of March 31, 2011	5		4
Impact on effective tax rate
Balance of unrecognized tax benefits	5		4
Effective Tax Rate and Unrecognized Tax Benefits (Textuals) [Abstract]
Effective tax rate	32.60%	37.60%
Positive cash flow due to tax accounting method for repair costs			5
Other Registrants [Member]
Changes for unrecognized tax benefits [Abstract]
Balance as of March 31, 2011	59
Impact on effective tax rate
Tax positions impacting the effective tax rate	12
Tax positions not impacting the effective tax rate	47
Balance of unrecognized tax benefits	59
Accrued interest for unrecognized tax benefits
Interest accrued as of December 31, 2010	2
Interest accrued during the period	2
Balance as of March 31, 2011	4
Southern Power [Member]
Changes for unrecognized tax benefits [Abstract]
Unrecognized tax benefits as of December 31, 2010	2
Reductions due to expired statute of limitations	0
Balance as of March 31, 2011	2		2
Impact on effective tax rate
Balance of unrecognized tax benefits	2		2
Effective Tax Rate and Unrecognized Tax Benefits (Textuals) [Abstract]
Effective tax rate	35.30%	26.70%
Positive cash flow due to tax accounting method for repair costs			$ 6