Summary Of Significant Accounting Policies (Schedule Of Depreciation Rates On Average Depreciable Property) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Depreciation rates on average depreciable property	2.50%	2.60%	2.60%
Entergy Arkansas [Member]
Depreciation rates on average depreciable property	2.50%	2.60%	2.90%
Entergy Gulf States Louisiana [Member]
Depreciation rates on average depreciable property	1.80%	1.80%	1.80%
Entergy Louisiana [Member]
Depreciation rates on average depreciable property	2.40%	2.50%	2.40%
Entergy Mississippi [Member]
Depreciation rates on average depreciable property	2.60%	2.60%	2.60%
Entergy New Orleans [Member]
Depreciation rates on average depreciable property	3.00%	3.00%	3.10%
Entergy Texas [Member]
Depreciation rates on average depreciable property	2.40%	2.20%	2.30%
System Energy [Member]
Depreciation rates on average depreciable property	2.80%	2.80%	2.90%