Acquisitions and Dispositions (Details) (USD $)	1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended			4 Months Ended	12 Months Ended
	Oct. 31, 2007	Dec. 31, 2010	Dec. 31, 2010 Harrison Country [Member]	Oct. 31, 2007 Entergy Wholesale Commodities [Member]	Dec. 31, 2011 Entergy Wholesale Commodities [Member]	Dec. 31, 2010 Entergy Wholesale Commodities [Member]	Dec. 31, 2009 Entergy Wholesale Commodities [Member]	Apr. 30, 2007 Palisades [Member] Entergy Wholesale Commodities [Member] MW	Dec. 31, 2011 Palisades [Member] Entergy Wholesale Commodities [Member]	Dec. 31, 2010 Palisades [Member] Entergy Wholesale Commodities [Member]	Dec. 31, 2009 Palisades [Member] Entergy Wholesale Commodities [Member]	Apr. 30, 2011 Acadia [Member]	Apr. 30, 2011 Acadia Unit 2 [Member]	Dec. 31, 2011 Rhode Island State [Member]
Acquisitions And Dispositions (Textual) [Abstract]
Percent of acquisition												50.00%	100.00%
Amount paid for ownership in Facility common assets												$ 300,000,000		$ 346,000,000
Time period of PPA executed by Non-Utility Nuclear business								15 years
Percentage of the plant's output covered by PPA								100.00%
Price under PPA, lower range, per MWH								43.50
Price under PPA, upper range, per MWH								61.50
Average price under PPA								51
Amounts amortized to revenue									43,000,000	46,000,000	53,000,000
Amounts to be amortized to revenue for 2012									17,000,000
Amounts to be amortized to revenue for 2013									18,000,000
Amounts to be amortized to revenue for 2014									16,000,000
Amounts to be amortized to revenue for 2015									15,000,000
Amounts to be amortized to revenue for 2016									13,000,000
Annual cap for future payment to NYPA for power sold from Fitz Patrick plant, per MWH				24,000,000
Contingent consideration recorded as plant					72,000,000	72,000,000	72,000,000
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Energy plant sold			219,000,000
Gain on sale of plant net of tax			27,200,000
Future payment to NYPA for power sold from Fitz Patrick plant, per MWH	3.91
Annual cap for future payment to NYPA for power sold from Indian point 3 plant	48,000,000
Future payment to NYPA for power sold from Indian point 3 plant, per MWH	6.59
Share of the plant sold (in percentage)		61.00%
Realized gain of plant sold		$ 44,200,000