Stock-Based Compensation (Schedule Of Financial Information Of Options) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 5.0	$ 5.0	$ 4.0
Compensation expense included in Entergy's Consolidated Net Income for the year	3.9	3.8	4.3
Tax benefit (expense) recognized in Entergy's Consolidated Net Income for the year	1.0	1.0	1.1
Compensation cost capitalized as part of fixed assets and inventory	1.5	1.4	0.7
Restricted Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	27.0	25.0	25.0
Compensation expense included in Entergy's Consolidated Net Income for the year	23.1	20.2	19.8
Tax benefit (expense) recognized in Entergy's Consolidated Net Income for the year	5.9	5.1	5.1
Compensation cost capitalized as part of fixed assets and inventory	8.5	7.1	5.7
Long-Term Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense included in Entergy's Consolidated Net Income for the year	12.6	11.1	11.5
Tax benefit (expense) recognized in Entergy's Consolidated Net Income for the year	3.2	2.8	2.9
Compensation cost capitalized as part of fixed assets and inventory	4.9	4.0	3.3
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	4.0	6.0	3.1
Compensation expense included in Entergy's Consolidated Net Income for the year	2.0	2.2	2.9
Tax benefit (expense) recognized in Entergy's Consolidated Net Income for the year	0.5	0.6	0.7
Compensation cost capitalized as part of fixed assets and inventory	$ 0.9	$ 0.9	$ 0.7

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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