Leases (Narrative) (Details)	1 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 1988 USD ($) transaction	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 1989 USD ($) transaction	Jun. 30, 2016 USD ($)	Oct. 31, 2015 USD ($)	Aug. 31, 2010 USD ($)
Rent expense			$ 44,400,000	$ 63,900,000	$ 59,000,000
Net regulatory liability related to sale and leaseback transaction								$ 107,000,000
Entergy Arkansas [Member]
Rent expense			8,000,000	13,600,000	12,000,000
Payments For Railcar Operating Lease			3,400,000	4,700,000	4,800,000
Value of non interest bearing first mortgage bonds									$ 124,100,000
Regulatory Asset			$ 128,500,000	85,700,000
Purchased Percentage Of Capacity And Energy Based On Agreement			17.10%
Entergy Louisiana [Member]
Portion of Waterford 3 purchase price satisfied through issuance of debt	$ 52,000,000
Rent expense			$ 17,800,000	21,800,000	20,700,000
Payments For Railcar Operating Lease			300,000	1,100,000	1,700,000
Cash payment representing the purchase price to acquire the undivided interests in Waterford 3	$ 60,000,000
Net regulatory liability related to sale and leaseback transaction			$ 53,900,000	68,300,000			$ 16,100,000
Purchased Percentage Of Capacity And Energy Based On Agreement			26.90%
Entergy Louisiana [Member] | Purchased Power Agreement [Domain]
Percentage Of Capacity And Energy Purchased Under Purchased Power Agreement			50.00%
Entergy Louisiana [Member] | Waterford 3 [Member]
Number of sale leaseback transactions | transaction						3
Sale and lease back transaction amount						$ 353,600,000
Implicit rate of future minimum lease payments			8.09%
Liability related to undivided interests in Waterford 3				62,700,000
Reduction in liability related to undivided interest in Waterford 3				2,700,000
Reduced liability related to undivided interests in Waterford 3				60,000,000
Entergy Mississippi [Member]
Rent expense			$ 4,000,000	5,400,000	4,300,000
Regulatory Asset			$ 82,000,000	77,500,000
Purchased Percentage Of Capacity And Energy Based On Agreement			31.30%
Oil Tank Facilities Lease Payments			$ 1,600,000	1,600,000	1,600,000
Entergy New Orleans [Member]
Rent expense			900,000	1,600,000	1,200,000
Regulatory Asset			$ 40,100,000	29,400,000
Purchased Percentage Of Capacity And Energy Based On Agreement			24.70%
Entergy Texas [Member]
Rent expense			$ 2,800,000	4,000,000	3,800,000
Regulatory Asset			33,500,000	25,800,000
Capacity expense under purchase power agreements accounted for as operating leases			$ 26,100,000	29,900,000	29,200,000
Entergy Texas [Member] | Purchased Power Agreement [Domain]
Percent of minimum payments			100.00%
System Energy [Member]
Rent expense			$ 1,600,000	2,900,000	$ 2,000,000
Regulatory Asset			69,700,000	54,800,000
System Energy [Member] | Grand Gulf [Member]
Year Two			$ 17,188,000
Number of sale leaseback transactions | transaction		2
Sale and lease back transaction amount		$ 500,000,000
Implicit rate of future minimum lease payments			5.13%
Regulatory Asset			$ 0
Net regulatory liability related to sale and leaseback transaction			$ 55,600,000	$ 55,600,000