Property, Plant, And Equipment (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Construction expenditures in accounts payable	$ 496.4	$ 745.0
Entergy Arkansas [Member]
Construction expenditures in accounts payable	39.6	59.7
Entergy Louisiana [Member]
Construction expenditures in accounts payable	330.4	460.5
Entergy Mississippi [Member]
Construction expenditures in accounts payable	24.1	31.4
Entergy New Orleans [Member]
Construction expenditures in accounts payable	4.0	9.2
Entergy Texas [Member]
Construction expenditures in accounts payable	44.6	116.8
System Energy [Member]
Construction expenditures in accounts payable	$ 17.7	$ 17.7