Risk Management and Fair Values (Reconciliation Of Changes In The Net Assets (Liabilities) For The Fair Value Of Derivatives Classified As Level 3 In The Fair Value Hierarchy) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Entergy Arkansas [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	$ 0.7	$ 0
Unrealized gains included as a regulatory liability/asset	15.0	7.8
Settlements	(15.1)	(5.1)
Balance as of March 31,	0.6	2.7
Entergy Gulf States Louisiana [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	14.4	6.7
Unrealized gains included as a regulatory liability/asset	(2.0)	7.7
Settlements	(7.4)	(9.0)
Balance as of March 31,	5.0	5.4
Entergy Louisiana [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	11.1	5.7
Unrealized gains included as a regulatory liability/asset	(0.2)	5.3
Settlements	(7.1)	(8.0)
Balance as of March 31,	3.8	3.0
Entergy Mississippi [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	3.4	1.0
Unrealized gains included as a regulatory liability/asset	0.8	11.6
Settlements	(3.3)	(7.8)
Balance as of March 31,	0.9	4.8
Entergy New Orleans [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	4.1	2.0
Unrealized gains included as a regulatory liability/asset	(1.1)	2.0
Settlements	(1.6)	(3.0)
Balance as of March 31,	1.4	1.0
Entergy Texas [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	12.3	18.4
Unrealized gains included as a regulatory liability/asset	(10.3)	1.8
Settlements	1.4	(12.8)
Balance as of March 31,	3.4	7.4
Electricity Swaps And Options [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	215.0	(133.0)
Realized gains (losses) included in earnings	52	5
Unrealized gains (losses) included in earnings	(87)	16
Unrealized losses included in OCI	(26)	(162)
Unrealized gains (losses) included as a regulatory liability/asset	0	0
Purchases	10	5
Settlements	(19.0)	183.0
Balance as of March 31,	145.0	(86.0)
Fixed Transmission Rights (FTRs) [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at Beginning of Period	47.0	34.0
Realized gains (losses) included in earnings	0	0
Unrealized gains (losses) included in earnings	0	0
Unrealized losses included in OCI	0	0
Unrealized gains (losses) included as a regulatory liability/asset	1	37
Purchases	0	0
Settlements	(33.0)	(46.0)
Balance as of March 31,	$ 15.0	$ 25.0