Stock-Based Compensation (Financial Information For Stock Options) (Details) - Parent Company [Member] - Employee Stock Option [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employee service share-based compensation, aggregate disclosures
Compensation expense included in Entergy's net income	$ 1.1	$ 1.0	$ 3.2	$ 3.1
Tax benefit recognized in Entergy's net income	0.4	0.4	1.2	1.2
Compensation cost capitalized as part of fixed assets and inventory	$ 0.1	$ 0.2	$ 0.5	$ 0.5