Income Taxes Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2015	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2020
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	$ 24.7
Increase (Reduction) in income tax resulting from Act 55 financing settlement	32.0
Act 55 final recorded income tax reduction	58.0
Increase (Decrease) in Income Taxes	26.0
Regulatory Charge for Hurricane Isaac Act 55 Tax Obligation to Customers	29.0
Regulatory Charge for Hurricane Isaac Act 55 Tax Obligation to Customers (Net-of-tax)	21.0
Subsequent Event [Member]
CARES Act Deferred Tax Expense		$ 64.0
CARES Act annual payroll tax installment due resulting from deferred tax payments				$ 32.0	$ 32.0
Reduction in federal uncertain tax positions						$ 400.0
Entergy Arkansas [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	4.8
Entergy Louisiana [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	8.6
Entergy Mississippi [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	2.7
Entergy New Orleans [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	1.5
System Energy [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	1.3
Change in accounting method for tax purposes, effect of change on taxable income			$ 1,200.0
Entergy Texas [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	$ 2.7