Risk Management and Fair Values (Derivative Instruments Not Designated As Hedging Instruments On The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fuel, Fuel Related Expenses And Gas Purchased For Resale [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recognized in AOCI		$ 0.0	$ 0.0	$ 0.0
Amount of gain (loss) recorded in income	[1]	(41.0)	(8.0)	13.0
Purchased Power Expense [Member] | Fixed Transmission Rights (FTRs) [Member] | Not Designated As Hedging Instrument [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recognized in AOCI		0.0	0.0	0.0
Amount of gain (loss) recorded in income	[2]	166.0	229.0	3.0
Competitive Businesses Operating Revenues [Member] | Electricity Swaps And Options [Member] | Not Designated As Hedging Instrument [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recognized in AOCI		12.0	(13.0)	1.0
Amount of gain (loss) recorded in income		(19.0)	56.0	(50.0)
Entergy Louisiana [Member] | Fuel, Fuel Related Expenses And Gas Purchased For Resale [Member] | Natural Gas Swaps [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		(33.2)	(5.5)	10.5
Entergy Louisiana [Member] | Purchased Power Expense [Member] | Fixed Transmission Rights (FTRs) [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		55.4	103.5	0.5
Entergy Mississippi [Member] | Fuel, Fuel Related Expenses And Gas Purchased For Resale [Member] | Natural Gas Swaps [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		(6.1)	(2.5)	2.5
Entergy Mississippi [Member] | Purchased Power Expense [Member] | Fixed Transmission Rights (FTRs) [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		16.5	19.0	1.0
Entergy New Orleans [Member] | Fuel, Fuel Related Expenses And Gas Purchased For Resale [Member] | Natural Gas Swaps [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		(1.4)	(0.2)	0.1
Entergy New Orleans [Member] | Purchased Power Expense [Member] | Fixed Transmission Rights (FTRs) [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		8.5	16.5	1.2
Entergy Arkansas [Member] | Purchased Power Expense [Member] | Fixed Transmission Rights (FTRs) [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		68.7	21.6	(0.1)
Entergy Texas [Member] | Purchased Power Expense [Member] | Fixed Transmission Rights (FTRs) [Member]
Effect of Derivative instruments not designated as hedging instruments on the consolidated statements of income
Amount of gain (loss) recorded in income		$ 16.8	$ 65.8	$ 0.8

[1] (a)Due to regulatory treatment, the natural gas swaps are marked-to-market through fuel, fuel-related expenses, and gas purchased for resale and then such amounts are simultaneously reversed and recorded as an offsetting regulatory asset or liability. The gains or losses recorded as fuel expenses when the swaps are settled are recovered or refunded through fuel cost recovery mechanisms.

[2] (b)Due to regulatory treatment, the changes in the estimated fair value of FTRs for the Utility operating companies are recorded through purchased power expense and then such amounts are simultaneously reversed and recorded as an offsetting regulatory asset or liability. The gains or losses recorded as purchased power expense when the FTRs for the Utility operating companies are settled are recovered or refunded through fuel cost recovery mechanisms.