Revolving Credit Facilities, Lines Of Credit And Short-Term Borrowings (Short-Term Borrowings And The Outstanding Short-Term Borrowings) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Entergy Arkansas [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	$ 250
Entergy Gulf States Louisiana [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	200
Borrowings	7
Entergy Louisiana [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	250
Entergy Mississippi [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	175
Entergy New Orleans [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	100
Entergy Texas [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	200
System Energy [Member]
Short-term borrowings and the outstanding short-term borrowings
Authorized	$ 200