Revolving Credit Facilities, Lines Of Credit And Short-Term Borrowings (Notes Payable By Variable Interest Entities) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Three Point Three Eight Percent Series R Due August Two Thousand Twenty [Member] | Entergy Louisiana River Bend VIE [Member]
Notes payable by variable interest entities
Debt Instrument, Interest Rate, Stated Percentage	3.38%
Amount	$ 70
Three Point Nine Two Percent Series H Dues February Two Thousand Twenty One [Member] | Entergy Louisiana Waterford VIE [Member]
Notes payable by variable interest entities
Debt Instrument, Interest Rate, Stated Percentage	3.92%
Amount	$ 40
Three Point Seven Eight Percent Series I Due October Two Thousand Eighteen [Member] | System Energy VIE [Member]
Notes payable by variable interest entities
Debt Instrument, Interest Rate, Stated Percentage	3.78%
Amount	$ 85
Three Point Six Five Percent Series L Notes Due July Two Thousand Twenty One [Member] | Entergy Arkansas VIE [Member]
Notes payable by variable interest entities
Debt Instrument, Interest Rate, Stated Percentage	3.65%
Amount	$ 90
Three Point One Seven Percent Series M Notes Due December Two Thousand Twenty Three [Member] | Entergy Arkansas VIE [Member]
Notes payable by variable interest entities
Amount	$ 40
Three Point Two Two Percent Series I Due December Two Thousand Twenty Three [Member] | Entergy Louisiana Waterford VIE [Member]
Notes payable by variable interest entities
Debt Instrument, Interest Rate, Stated Percentage	3.22%
Amount	$ 20
Three Point One Seven Percent Series M Due December Two Thousand Twenty Three [Member] | Entergy Arkansas VIE [Member]
Notes payable by variable interest entities
Debt Instrument, Interest Rate, Stated Percentage	3.17%