Decommissioning Trust Funds (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts			$ 361,000,000		$ 329,000,000
Amortized cost of debt securities	1,957,000,000		1,957,000,000		1,843,000,000
Average coupon rate of debt securities	3.27%		3.27%
Average duration of debt securities, years			5 years 4 months 24 days
Average maturity of debt securities, years			8 years 1 month 10 days
Proceeds from the dispositions of debt securities	465,000,000	284,000,000	1,447,000,000	1,064,000,000
Gains from dispositions of debt securities, gross	11,000,000	3,000,000	23,000,000	25,000,000
Losses from dispositions of debt securities, gross	2,000,000	4,000,000	5,000,000	7,000,000
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	279,100,000		279,100,000		248,900,000
Average coupon rate of debt securities	2.62%		2.62%
Average duration of debt securities, years			4 years 9 months 26 days
Average maturity of debt securities, years			5 years 5 months 5 days
Proceeds from the dispositions of debt securities	85,100,000	30,300,000	155,400,000	173,400,000
Gains from dispositions of debt securities, gross	8,100,000	600,000	8,500,000	9,300,000
Losses from dispositions of debt securities, gross	13,000	100,000	300,000	200,000
Entergy Gulf States Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	225,000,000		225,000,000		199,100,000
Average coupon rate of debt securities	4.40%		4.40%
Average duration of debt securities, years			5 years 9 months 22 days
Average maturity of debt securities, years			10 years 2 months 19 days
Proceeds from the dispositions of debt securities	52,500,000	19,500,000	127,900,000	66,200,000
Gains from dispositions of debt securities, gross	500,000	300,000	1,200,000	6,600,000
Losses from dispositions of debt securities, gross	100,000	20,000	300,000	30,000
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	132,600,000		132,600,000		120,600,000
Average coupon rate of debt securities	3.04%		3.04%
Average duration of debt securities, years			5 years 0 months 22 days
Average maturity of debt securities, years			8 years 0 months 18 days
Proceeds from the dispositions of debt securities	6,200,000	2,700,000	35,900,000	12,200,000
Gains from dispositions of debt securities, gross	30,000	10,000	200,000	60,000
Losses from dispositions of debt securities, gross	3,700	10,000	7,800	30,000
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	242,700,000		242,700,000		223,400,000
Average coupon rate of debt securities	2.03%		2.03%
Average duration of debt securities, years			4 years 3 months 22 days
Average maturity of debt securities, years			5 years 9 months 4 days
Proceeds from the dispositions of debt securities	101,400,000	53,400,000	333,000,000	144,600,000
Gains from dispositions of debt securities, gross	200,000	100,000	1,600,000	900,000
Losses from dispositions of debt securities, gross	$ 200,000	$ 800,000	$ 500,000	$ 1,200,000