Income Taxes (Summary of Accrued Balances for Possible Payment of Interest Related to Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 32.0	$ 39.0	$ 50.0
Entergy Arkansas [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	8.4	7.8	4.3
Entergy Louisiana [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	5.1	1.5	4.1
Entergy Mississippi [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	3.2	2.1	3.1
Entergy New Orleans [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0.6	0.6	6.4
Entergy Texas [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0.5	0.0	1.1
System Energy [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 2.9	$ 1.9	$ 1.9