Income Taxes (Summary Of Accrued Interest And Penalties Related To Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accrued income tax interest and penalties	$ 44.0	$ 38.0	$ 30.0
Entergy Arkansas [Member]
Accrued income tax interest and penalties	1.7	1.6	1.4
Entergy Louisiana [Member]
Accrued income tax interest and penalties	17.9	14.1	8.4
Entergy Mississippi [Member]
Accrued income tax interest and penalties	1.2	1.0	0.8
Entergy New Orleans [Member]
Accrued income tax interest and penalties	2.7	2.1	1.5
Entergy Texas [Member]
Accrued income tax interest and penalties	0.9	0.4	1.2
System Energy [Member]
Accrued income tax interest and penalties	$ 13.2	$ 8.5	$ 3.7