Risk Management and Fair Values (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012 Y	Sep. 30, 2011	Sep. 30, 2012 Y	Sep. 30, 2011
Risk Management and Fair Values [Abstract]
Cash flow hedges relating to power sales as part of net unrealized gains			$ 196,000,000
Reclassified from accumulated other comprehensive income (OCI) to operating revenues			140,000,000
Maturity of cash flow hedges, before taxes	61,000,000	48,000,000	232,000,000	109,000,000
Maturity of cash flow hedges, Tax	21,000,000	17,000,000	81,000,000	38,000,000
Maximum length of time over which Company is currently hedging the variability in future cash flows for forecasted power transactions, years	2.25		2.25
Planned generation sold forward from non utility nuclear power plants in the next three quarters	89.00%
Planned Generation Sold Forward under financial derivatives	48.00%		48.00%
Change in cash flow hedges due to ineffectiveness	4,500,000	6,200,000	5,100,000	8,400,000
Dollar amount of hedge contract in a liability position	2,000,000		2,000,000
Total volume of natural gas swaps outstanding (MMBtu)	30,900,000		30,900,000
Cash flow hedges in-the-money contracts	$ 218,000,000		$ 218,000,000
Entergy Gulf States Louisiana [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu)	9,140,000		9,140,000
Entergy Louisiana [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu)	14,800,000		14,800,000
Entergy Mississippi [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu)	6,960,000		6,960,000