Risk Management and Fair Values (Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Millions		Mar. 31, 2016		Dec. 31, 2015
Assets:
Derivative asset as hedging instrument offset		$ (66.0)		$ (68.0)
Other Non-Current Liabilities [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	[1]	1.0		2.0
Derivative liability as hedging instrument offset	[2]	(1.0)		(2.0)
Derivative Liability	[3],[4]	0.0		0.0
Other Deferred Debits And Other Assets [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset	[1]	20.0		17.0
Derivative asset as hedging instrument offset	[2]	(1.0)		(2.0)
Derivative Asset	[3],[4]	19.0		15.0
Prepayments And Other [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset	[1]	120.0		173.0
Derivative asset as hedging instrument offset	[2]	(26.0)		(34.0)
Derivative Asset	[3],[4]	94.0		139.0
Prepayments And Other [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset	[1]	94.0		54.0
Derivative asset as hedging instrument offset	[2]	(24.0)		(13.0)
Derivative Asset	[3],[4]	70.0		41.0
Prepayments And Other [Member] | Fixed Transmission Rights (FTRs) [Member] | Utility and Entergy Wholesale Commodities [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset	[1]	9.0		24.0
Derivative asset as hedging instrument offset	[2]			(1.0)
Derivative Asset	[3],[4]	9.0		23.0
Other Current Liabilities [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	[1]	1.0		14.0
Derivative liability as hedging instrument offset	[2]	(1.0)		(14.0)
Derivative Liability	[3],[4]	0.0		0.0
Other Current Liabilities [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	[1]	49.0		38.0
Derivative liability as hedging instrument offset	[2]	(49.0)		(32.0)
Derivative Liability	[3],[4]	0.0		6.0
Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Utility [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	[1]	9.0		9.0
Derivative liability as hedging instrument offset		0.0	[1]	0.0	[2]
Derivative Liability	[3],[4]	9.0		9.0
Entergy Louisiana [Member] | Prepayments And Other [Member] | Fixed Transmission Rights (FTRs) [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset		3.3		8.5
Entergy Louisiana [Member] | Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability		7.6		7.0
Entergy Mississippi [Member] | Prepayments And Other [Member] | Fixed Transmission Rights (FTRs) [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset		0.9		2.4
Entergy Mississippi [Member] | Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability		1.8		1.3
Entergy New Orleans [Member] | Prepayments And Other [Member] | Fixed Transmission Rights (FTRs) [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset		0.6		1.5
Entergy New Orleans [Member] | Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability				0.5
Entergy Arkansas [Member] | Prepayments And Other [Member] | Fixed Transmission Rights (FTRs) [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset		3.7		7.9
Entergy Texas [Member] | Prepayments And Other [Member] | Fixed Transmission Rights (FTRs) [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset		$ 0.9		$ 2.2

[1] Represents the gross amounts of recognized assets/liabilities

[2] Represents the netting of fair value balances with the same counterparty

[3] Excludes cash collateral in the amount of $9 million posted and $68 million held as of December 31, 2015. There was no cash collateral required to be posted as of March 31, 2016. Also excludes letters of credit in the amount of $0.4 million posted and $66 million held as of March 31, 2016.

[4] Represents the net amounts of assets /liabilities presented on the Entergy Consolidated Balance Sheets