Decommissioning Trust Funds (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Decommissioning Trust Funds [Abstract]
Receivables recorded for beneficial interests in decommissioning trust funds	$ 1,500,000		$ 1,500,000
Decommissioning Fund Investments	5,671,074		5,671,074		$ 5,349,953
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts			400,000		342,000
Amortized cost of debt securities	$ 2,199,000		$ 2,199,000		2,124,000
Average coupon rate of debt securities	3.19%		3.19%
Average duration of debt securities, years			5 years 11 months 14 days
Average maturity of debt securities, years			9 years 4 months 22 days
Proceeds from the dispositions of debt securities	$ 564,000	$ 539,000	$ 1,797,000	$ 1,488,000
Gains from dispositions of debt securities, gross	6,000	13,000	26,000	58,000
Losses from dispositions of debt securities, gross	1,000	4,000	6,000	7,000
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments	823,816		823,816		771,313
Amortized cost of debt securities	$ 308,400		$ 308,400		301,800
Average coupon rate of debt securities	2.63%		2.63%
Average duration of debt securities, years			5 years 2 months 17 days
Average maturity of debt securities, years			5 years 11 months 20 days
Proceeds from the dispositions of debt securities	$ 61,200	44,000	$ 165,000	190,800
Gains from dispositions of debt securities, gross	400	400	1,600	5,800
Losses from dispositions of debt securities, gross	40	100	300	100
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments	1,124,821		$ 1,124,821		1,042,293
Percentage Interest in River Bend			30.00%
Amortized cost of debt securities	$ 419,200		$ 419,200		399,200
Average coupon rate of debt securities	3.83%		3.83%
Average duration of debt securities, years			5 years 8 months 20 days
Average maturity of debt securities, years			11 years 4 months 22 days
Proceeds from the dispositions of debt securities	$ 54,700	28,400	$ 178,200	93,600
Gains from dispositions of debt securities, gross	400	200	3,000	1,700
Losses from dispositions of debt securities, gross	100	100	200	300
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments	764,903		764,903		701,460
Amortized cost of debt securities	$ 302,300		$ 302,300		$ 270,700
Average coupon rate of debt securities	1.79%		1.79%
Average duration of debt securities, years			5 years 2 months 6 days
Average maturity of debt securities, years			6 years 3 months 27 days
Proceeds from the dispositions of debt securities	$ 103,500	163,400	$ 392,900	325,400
Gains from dispositions of debt securities, gross	700	2,400	3,200	3,200
Losses from dispositions of debt securities, gross	60	$ 200	400	$ 300
NYPA [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments	$ 1,500,000		$ 1,500,000