Property, Plant, And Equipment (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Construction expenditures in accounts payable	$ 1,400.0	$ 406.0
Entergy Arkansas [Member]
Construction expenditures in accounts payable	50.4	67.9
Entergy Louisiana [Member]
Construction expenditures in accounts payable	1,100.0	115.1
Entergy Mississippi [Member]
Construction expenditures in accounts payable	24.1	34.2
Entergy New Orleans [Member]
Construction expenditures in accounts payable	6.4	18.4
Entergy Texas [Member]
Construction expenditures in accounts payable	204.3	88.1
System Energy [Member]
Construction expenditures in accounts payable	$ 18.0	$ 23.2