Revolving Credit Facilities, Lines Of Credit And Short-Term Borrowings (Notes Payable By Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013 Entergy Gulf States Louisiana VIE [Member]	Dec. 31, 2012 Nine Percent Series H Notes Due June Two Thousand And Thirteen [Member] Entergy Arkansas VIE [Member]	Dec. 31, 2012 Five Point Six Nine Percent Series I Notes Due July Two Thousand Fourteen [Member] Entergy Arkansas VIE [Member]	Dec. 31, 2012 Three Point Two Three Percent Series J Notes Due July Two Thousand Sixteen [Member] Entergy Arkansas VIE [Member]	Dec. 31, 2012 Two Point Six Two Percent Series K Notes Due December Two Thousand Seventeen [Member] Entergy Arkansas VIE [Member]	Dec. 31, 2012 Five Point Five Six Percent Series N Notes Due May Two Thousand Thirteen [Member] Entergy Gulf States Louisiana VIE [Member]	Dec. 31, 2012 Three Point Two Five Percent Series Q Due July Two Thousand Seventeen [Member] Entergy Gulf States Louisiana VIE [Member]	Dec. 31, 2012 Five Point Six Nine Percent Series E Notes Due July Two Thousand Fourteen [Member] Entergy Louisiana VIE [Member]	Dec. 31, 2012 Three Point Three Percent Series F Note Due March Two Thousand Sixteen [Member] Entergy Louisiana VIE [Member]	Dec. 31, 2012 Three Point Two Five Percent Series G Due July Two Thousand Seventeen [Member] Entergy Louisiana VIE [Member]	Dec. 31, 2012 Six Point Two Nine Percent Series F Notes Due September Two Thousand Thirteen [Member] System Energy VIE [Member]	Dec. 31, 2012 Five Point Three Three Percent Series G Notes Due April Two Thousand Fifteen [Member] System Energy VIE [Member]	Dec. 31, 2012 Four Point Zero Two Percent Series H Notes Due February Two Thousand Seventeen [Member] System Energy VIE [Member]
Notes payable by variable interest entities
Interest Rate	3.38%
Amount		$ 30	$ 70	$ 55	$ 60	$ 75	$ 75	$ 50	$ 20	$ 25	$ 70	$ 60	$ 50