Risk Management and Fair Values (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Other non-current liabilities [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Designated as Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	$ 1	$ 47
Derivative liability as hedging instrument offset	(1)	(30)
Other non-current liabilities [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Not Designated as Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	0	7
Derivative liability as hedging instrument offset	0	(7)
Other deferred debits and other assets [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Designated as Hedging Instrument [Member]
Assets:
Derivative Asset, Fair value	112	82
Derivative asset as hedging instrument offset	(1)	(29)
Other deferred debits and other assets [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Not Designated as Hedging Instrument [Member]
Assets:
Derivative Asset, Fair value	0	14
Derivative asset as hedging instrument offset	0	(8)
Prepayments and other [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Designated as Hedging Instrument [Member]
Assets:
Derivative Asset, Fair value	197	160
Derivative asset as hedging instrument offset	(25)	(7)
Prepayments and other [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Not Designated as Hedging Instrument [Member]
Assets:
Derivative Asset, Fair value	37	2
Derivative asset as hedging instrument offset	(8)	0
Other current liabilities [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Designated as Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	0	5
Derivative liability as hedging instrument offset	0	(5)
Other current liabilities [Member] | Electricity forwards, swaps and options [Member] | Entergy Wholesale Commodities [Member] | Not Designated as Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	33	2
Derivative liability as hedging instrument offset	(33)	(2)
Other current liabilities [Member] | Natural gas swaps [Member] | Utility [Member] | Not Designated as Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value	30	2
Derivative liability as hedging instrument offset	$ 0	$ 0