Property, Plant, And Equipment (Narrative) (Details) (USD $) In Millions, unless otherwise specified																	3 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Entergy Arkansas [Member]	Dec. 31, 2012 Entergy Arkansas [Member]	Sep. 30, 2013 Entergy Gulf States Louisiana [Member]	Dec. 31, 2012 Entergy Gulf States Louisiana [Member]	Sep. 30, 2013 Entergy Louisiana [Member]	Dec. 31, 2012 Entergy Louisiana [Member]	Sep. 30, 2013 Entergy Mississippi [Member]	Dec. 31, 2012 Entergy Mississippi [Member]	Sep. 30, 2013 Entergy New Orleans	Dec. 31, 2012 Entergy New Orleans	Sep. 30, 2013 Entergy Texas [Member]	Dec. 31, 2012 Entergy Texas [Member]	Sep. 30, 2013 System Energy [Member]	Dec. 31, 2012 System Energy [Member]	Sep. 30, 2013 Vermont Yankee [Member]	Dec. 31, 2014 Minimum [Member] Vermont Yankee [Member]	Dec. 31, 2014 Maximum [Member] Vermont Yankee [Member]
Construction expenditures in accounts payable	$ 91.5	$ 267.0	$ 25.6	$ 56.3	$ 17.7	$ 9.7	$ 12.4	$ 110.4	$ 0.8	$ 4.8	$ 1.4	$ 1.9	$ 4.7	$ 8.6	$ 5.2	$ 13.5
Estimated Fair Value of Nuclear Plant																	62
Carrying Value of Nuclear Plant																	349
Asset Impairment Charges																	291.5
After-Tax Asset Impairment Charge																	183.7
Increase in decommissioning liability																	58
Supplemental Unemployment Benefits, Severance Benefits																		$ 55	$ 60