Stock-Based Compensation (Financial Information For Stock Options) (Details) - Employee Stock Option [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee service share-based compensation, aggregate disclosures
Compensation expense included in Entergy's net income	$ 1.2	$ 1.0	$ 3.2	$ 3.0
Tax benefit recognized in Entergy's net income	0.3	0.3	0.8	0.8
Compensation cost capitalized as part of fixed assets and inventory	$ 0.4	$ 0.4	$ 1.2	$ 1.2