Property, Plant, And Equipment (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Construction expenditures in accounts payable	$ 324.0	$ 311.0
Entergy Arkansas [Member]
Construction expenditures in accounts payable	29.9	35.7
Entergy Louisiana [Member]
Construction expenditures in accounts payable	118.0	104.6
Entergy Mississippi [Member]
Construction expenditures in accounts payable	13.8	13.6
Entergy New Orleans [Member]
Construction expenditures in accounts payable	8.2	5.8
Entergy Texas [Member]
Construction expenditures in accounts payable	72.3	55.6
System Energy [Member]
Construction expenditures in accounts payable	$ 20.2	$ 26.3