Risk Management and Fair Values (Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Millions		Sep. 30, 2015		Dec. 31, 2014
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]	$ 4.0
Derivative liability as hedging instrument offset	[2]	(4.0)
Derivative Liability	[3],[4]	0.0
Other Non-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]	3.0		$ 8.0
Derivative liability as hedging instrument offset	[2]	(3.0)		(8.0)
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]	48.0		48.0
Derivative asset as hedging instrument offset	[2]	(4.0)		0.0
Derivative Asset	[3],[4]	44.0		48.0
Other Deferred Debits And Other Assets [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair Value, Gross Asset	[1]	6.0		9.0
Derivative asset as hedging instrument offset	[2]	(3.0)		(8.0)
Derivative Asset	[3],[4]	3.0		1.0
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]	122.0		149.0
Derivative asset as hedging instrument offset	[2]	(15.0)		(53.0)
Derivative Asset	[3],[4]	107.0		96.0
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]	19.0		97.0
Derivative asset as hedging instrument offset	[2]	(4.0)		(25.0)
Derivative Asset	[3],[4]	15.0		72.0
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]	48.0		50.0
Derivative asset as hedging instrument offset	[2]	(1.0)		(3.0)
Derivative Asset	[3],[4]	47.0		47.0
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]	6.0		24.0
Derivative liability as hedging instrument offset	[2]	(6.0)		(24.0)
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]	19.0		57.0
Derivative liability as hedging instrument offset	[2]	(13.0)		(55.0)
Derivative Liability	[3],[4]	6.0		2.0
Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Utility [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	[1]	10.0		20.0
Derivative liability as hedging instrument offset		0.0	[1]	0.0	[2]
Derivative Liability	[3],[4]	10.0		20.0
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		10.5		11.1
Entergy Louisiana [Member] | Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability		3.7		7.6
Entergy Mississippi [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability		1.5		2.8
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		4.3		3.4
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		4.0		4.1
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		0.4		0.9
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		11.7		0.7
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		$ 4.3		$ 12.3

[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 $25 million held as of December 31, 2014. No cash collateral was required to be posted or held as of September 30, 2015.

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