Income Taxes Income Taxes (Summary of Interest on Income Taxes Expense Related to Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense	$ (11.0)		$ (4.0)
Entergy Arkansas [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Expense	3.5	$ 1.6	0.4
Entergy Louisiana [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Expense		0.4	0.3
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense	(2.6)
Entergy Mississippi [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Expense		0.7	0.5
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense	(1.0)
Entergy New Orleans [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Expense		1.2	1.3
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense	(5.8)
Entergy Texas [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Expense		0.0	0.2
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense	(1.1)
System Energy [Member]
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 0.0		$ 0.2
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense		$ (10.2)