Decommissioning Trust Funds (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts	$ 335,000,000		$ 329,000,000
Amortized cost of debt securities	1,895,000,000		1,843,000,000
Average coupon rate of debt securities	3.36%
Average duration of debt securities, years	5 years 1 month 17 days
Average maturity of debt securities, years	7 years 7 months 6 days
Proceeds from the dispositions of debt securities	537,000,000	398,000,000
Gains from dispositions of debt securities, gross	6,000,000	6,000,000
Losses from dispositions of debt securities, gross	2,000,000	2,000,000
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	259,000,000		248,900,000
Average coupon rate of debt securities	2.78%
Average duration of debt securities, years	4 years 10 months 21 days
Average maturity of debt securities, years	5 years 7 months 6 days
Proceeds from the dispositions of debt securities	45,300,000	56,100,000
Gains from dispositions of debt securities, gross	100,000	1,400,000
Losses from dispositions of debt securities, gross	200,000	100,000
Entergy Gulf States Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	219,500,000		199,100,000
Average coupon rate of debt securities	4.42%
Average duration of debt securities, years	5 years 6 months 11 days
Average maturity of debt securities, years	8 years 0 months 29 days
Proceeds from the dispositions of debt securities	30,300,000	23,300,000
Gains from dispositions of debt securities, gross	200,000	1,100,000
Losses from dispositions of debt securities, gross	200,000	1,700
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	124,700,000		120,600,000
Average coupon rate of debt securities	3.06%
Average duration of debt securities, years	4 years 10 months 10 days
Average maturity of debt securities, years	7 years 9 months 29 days
Proceeds from the dispositions of debt securities	18,100,000	3,600,000
Gains from dispositions of debt securities, gross	200,000	40,000
Losses from dispositions of debt securities, gross	3,900	10,000
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	230,500,000		223,400,000
Average coupon rate of debt securities	1.98%
Average duration of debt securities, years	4 years 4 months 17 days
Average maturity of debt securities, years	6 years 1 month 10 days
Proceeds from the dispositions of debt securities	130,300,000	25,600,000
Gains from dispositions of debt securities, gross	1,000,000	20,000
Losses from dispositions of debt securities, gross	$ 300,000	$ 70,000