Stock-Based Compensation (Financial Information For Stock Options) (Details) (Parent Company [Member], Employee Stock Option [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Parent Company [Member] | Employee Stock Option [Member]
Employee service share-based compensation, aggregate disclosures
Compensation expense included in Entergy's net income	$ 1.0	$ 1.9	$ 3.2	$ 5.8
Tax benefit recognized in Entergy's net income	0.4	0.7	1.3	2.2
Compensation cost capitalized as part of fixed assets and inventory	$ 0.2	$ 0.3	$ 0.6	$ 1.1