Risk Management and Fair Values (Narrative) (Details) (Imported) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012 Y	Jun. 30, 2011	Jun. 30, 2012 Y	Jun. 30, 2011
Risk Management and Fair Values [Abstract]
Cash flow hedges relating to power sales as part of net unrealized gains			$ 365,000,000
Reclassified from accumulated other comprehensive income (OCI) to operating revenues			217,000,000
Maturity of cash flow hedges, before taxes	101,000,000	32,000,000	171,000,000	61,000,000
Maturity of cash flow hedges, Tax	35,000,000	11,000,000	60,000,000	21,000,000
Maximum length of time over which Company is currently hedging the variability in future cash flows for forecasted power transactions, years	2.50		2.50
Planned generation sold forward from non utility nuclear power plants in the next three quarters			90.00%
Planned Generation Sold Forward under financial derivatives	49.00%		49.00%
Total volume of natural gas swaps outstanding (MMBtu)	35,500,000		35,500,000
Cash flow hedges in-the-money contracts	$ 375,000,000		$ 375,000,000
Entergy Gulf States Louisiana [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu)	10,350,000		10,350,000
Entergy Louisiana [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu)	15,330,000		15,330,000
Entergy Mississippi [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu)	9,820,000		9,820,000