Property, Plant, And Equipment (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Construction expenditures in accounts payable	$ 1,783.0	$ 745.0
Entergy Arkansas [Member]
Construction expenditures in accounts payable	38.9	59.7
Entergy Louisiana [Member]
Construction expenditures in accounts payable	1,552.9	460.5
Entergy Mississippi [Member]
Construction expenditures in accounts payable	25.5	31.4
Entergy New Orleans [Member]
Construction expenditures in accounts payable	77.6	9.2
Entergy Texas [Member]
Construction expenditures in accounts payable	42.3	116.8
System Energy [Member]
Construction expenditures in accounts payable	$ 17.5	$ 17.7