Decommissioning Trust Funds (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax				$ (632,617)
Decommissioning Fund Investments	$ 6,920,164	$ 7,211,993
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts	6,393	80,069	$ 57,277
Amortized cost of debt securities	$ 2,511,000	2,539,000
Average coupon rate of debt securities	3.19%
Proceeds from the dispositions of debt securities	$ 2,406,000	3,163,000	2,409,000
Gains from dispositions of debt securities, gross	7,000	149,000	32,000
Losses from dispositions of debt securities, gross	$ 47,000	13,000	13,000
Average Duration of Debt Securities in Years	4 years 6 months
Average Maturity of Debt Securities, Years	7 years 11 months 4 days
Equity Securities, FV-NI, Unrealized Gain	$ (249,000)
Entergy Arkansas [Member]
Decommissioning Fund Investments	912,049	944,890
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 389,000	349,100
Average coupon rate of debt securities	2.87%
Proceeds from the dispositions of debt securities	$ 82,100	339,400	197,400
Gains from dispositions of debt securities, gross	100	17,700	1,800
Losses from dispositions of debt securities, gross	$ 2,900	600	800
Average Duration of Debt Securities in Years	4 years 9 months
Average Maturity of Debt Securities, Years	7 years 4 months 4 days
Equity Securities, FV-NI, Unrealized Gain	$ (49,300)
Entergy Louisiana [Member]
Decommissioning Fund Investments	$ 1,284,996	1,312,073
Percentage Interest in River Bend	30.00%
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 534,800	490,000
Average coupon rate of debt securities	4.04%
Proceeds from the dispositions of debt securities	$ 401,700	231,300	219,200
Gains from dispositions of debt securities, gross	2,100	12,000	3,900
Losses from dispositions of debt securities, gross	$ 7,500	400	400
Average Duration of Debt Securities in Years	6 years 6 months 2 days
Average Maturity of Debt Securities, Years	13 years 7 months 1 day
Equity Securities, FV-NI, Unrealized Gain	$ (61,600)
System Energy [Member]
Decommissioning Fund Investments	869,543	905,686
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 367,100	327,500
Average coupon rate of debt securities	3.15%
Proceeds from the dispositions of debt securities	$ 361,900	565,400	499,300
Gains from dispositions of debt securities, gross	500	1,400	3,500
Losses from dispositions of debt securities, gross	$ 6,100	3,300	$ 1,700
Average Duration of Debt Securities in Years	6 years 17 days
Average Maturity of Debt Securities, Years	8 years 10 months 11 days
Equity Securities, FV-NI, Unrealized Gain	$ (40,700)
Indian Point 3 [Member]
Decommissioning Fund Investments	781,000	798,000
Indian Point 1 [Member]
Decommissioning Fund Investments	471,000	491,000
Indian Point 2 [Member]
Decommissioning Fund Investments	598,000	621,000
Palisades [Member]
Decommissioning Fund Investments	444,000	458,000
Pilgrim [Member]
Decommissioning Fund Investments	1,028,000	1,068,000
Vermont Yankee [Member]
Decommissioning Fund Investments	532,000	613,000
Debt Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts	$ (1,000)	7,000
Equity Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts		$ 472,000