Income Taxes (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Income Taxes (Textual) [Abstract]
Net cash payments for income taxes	$ (401)	$ 276	$ 975
Net operating loss carryforward of State of Georgia	879
State income tax benefits as a result of utilization of State of Georgia net operating loss carryforward	51
Valuation allowance for the potential tax benefit	51
Tax regulatory assets	1,400	82
Tax regulatory liabilities	224
Recovery and amortization periods for regulatory assets (liabilities), average remaining service period	up to 15 years
Amortization of deferred investment tax credits	19	23	24
Percentage of extension bonus depreciation for property acquired		50.00%
Percentage of additional bonus depreciation for property acquired	100.00%
Additional bonus depreciation for property acquired future periods	50.00%
Increase in unrecognized tax benefits	(176)
Balance of unrecognized tax benefits	120	296	199	146
Significantly increase or decrease in the amount of the unrecognized tax benefits associated with a majority of Southern	next 12 months
Net positive cash flow		$ 297