Income Taxes Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2015	Dec. 31, 2022	Dec. 31, 2021
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
Reduction in unrecognized tax benefits related to federal and state taxes		$ 1,500.0
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
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
Change in accounting method for tax purposes, effect of change on taxable income		190.0		$ 2,200.0
Cost of goods sold - Decommissioning Liability		221.0
Deferred tax liability due to decommissioning liability in cost of goods sold		60.0
Reduction in unrecognized tax benefits related to federal and state taxes		1,100.0
Reduction in unrecognized tax benefits		74.0
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
Cost of goods sold - Decommissioning Liability		102.0
Deferred tax liability due to decommissioning liability in cost of goods sold		26.0
Federal and state taxes payable due to decommissioning liability in cost of goods sold		402.0
Reduction in unrecognized tax benefits related to federal and state taxes		$ 461.0
Entergy Texas [Member]
Permanent Tax Reduction Resulting From Certain Stock-Based Awards	$ 2.7