Risk Management and Fair Values (Fair Values Of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Other Non-Current Liabilities [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	$ 18.0	[1]	$ 1.0	[1],[2]
Derivative liability as hedging instrument offset	(11)	[1]	(1)	[1],[2]
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	19.0
Derivative liability as hedging instrument offset	(13)
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	46	[1],[2]	112	[1],[2]
Derivative asset as hedging instrument offset	(10)	[1],[2]	(1)	[1],[2]
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	24
Derivative asset as hedging instrument offset	(14)
Prepayments And Other [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair value	123	[1],[2]	197	[1],[2]
Derivative asset as hedging instrument offset			(25)	[1],[2]
Prepayments And Other [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset, Fair value	22		37
Derivative asset as hedging instrument offset			(8)
Other Current Liabilities [Member] | Electricity Swaps And Options [Member] | Entergy Wholesale Commodities [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value			33.0
Derivative liability as hedging instrument offset			(33)
Other Current Liabilities [Member] | Swap [Member] | Utility Plants [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value			30.0
Derivative liability as hedging instrument offset
Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Utility Plants [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	8.0
Entergy Gulf States Louisiana [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	2.6		8.6
Entergy Louisiana [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	3.4		12.4
Entergy Mississippi [Member] | Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	2.2		7.8
Entergy New Orleans [Member] | Other Current Liabilities [Member] | Natural Gas Swaps [Member] | Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value			$ 1.5

[1] The balances of derivative assets and liabilities in these tables are presented gross. Certain investments, including those not designated as hedging instruments, are subject to master netting agreements and are presented on the Entergy Consolidated Balance Sheets on a net basis in accordance with accounting guidance for Derivatives and Hedging.

[2] The balances of derivative assets and liabilities in these tables are presented gross. Certain investments, including those not designated as hedging instruments, are subject to master netting agreements and are presented on the Entergy Consolidated Balance Sheets on a net basis in accordance with accounting guidance for Derivatives and Hedging