Income Taxes (Summary Of Unrecognized Benefits That Would Affect Effective Income Tax Rate) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unrecognized tax benefits that would impact effective income tax rate	$ 176.0	$ 203.0	$ 521.0
Entergy Arkansas [Member]
Unrecognized tax benefits that would impact effective income tax rate	0.6	0.6	0
Entergy Gulf States Louisiana [Member]
Unrecognized tax benefits that would impact effective income tax rate	44.0	44.0	107.9
Entergy Louisiana [Member]
Unrecognized tax benefits that would impact effective income tax rate	87.9	92.4	281.3
Entergy Mississippi [Member]
Unrecognized tax benefits that would impact effective income tax rate	3.9	3.9	3.8
Entergy New Orleans [Member]
Unrecognized tax benefits that would impact effective income tax rate	0	0	0
Entergy Texas [Member]
Unrecognized tax benefits that would impact effective income tax rate	10.1	8.6	7.3
System Energy [Member]
Unrecognized tax benefits that would impact effective income tax rate	$ 3.3	$ 3.5	$ 0