Decommissioning Trust Funds (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Aug. 31, 2019	Jan. 01, 2019	Jan. 01, 2018
Debt Securities, Trading, Measurement Input	$ 506,000,000		$ 506,000,000		$ 389,000,000
Decommissioning Trust Funds [Abstract]
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax							$ (6,806,000)	$ (632,617,000)
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts	1,303,000	$ (825,000)	17,472,000	$ 1,708,000
Amortized cost of debt securities	$ 2,362,000,000		$ 2,362,000,000		2,511,000,000
Average coupon rate of debt securities	3.15%		3.15%
Average duration of debt securities, years			5 years 7 months 17 days
Average maturity of debt securities, years			9 years 7 days
Proceeds from the dispositions of debt securities	$ 407,000,000	2,377,000,000	$ 1,133,000,000	4,178,000,000
Gains from dispositions of debt securities, gross	11,000,000	4,000,000	20,000,000	6,000,000
Losses from dispositions of debt securities, gross	400,000	15,000,000	3,000,000	37,000,000
Equity Securities, FV-NI, Unrealized Gain	17,000,000		491,000,000
Debt Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts			16,000,000		(1,000,000)
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 396,800,000		$ 396,800,000		389,000,000
Average coupon rate of debt securities	2.78%		2.78%
Average duration of debt securities, years			5 years 6 months 25 days
Average maturity of debt securities, years			8 years 1 month 17 days
Proceeds from the dispositions of debt securities	$ 45,500,000	137,900,000	$ 78,700,000	259,300,000
Gains from dispositions of debt securities, gross	2,000,000	10,000.00	2,100,000	100,000
Losses from dispositions of debt securities, gross		600,000	100,000	3,000,000
Equity Securities, FV-NI, Unrealized Gain	2,600,000		96,500,000
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 561,000,000		$ 561,000,000		534,800,000
Average coupon rate of debt securities	3.85%		3.85%
Average duration of debt securities, years			6 years 6 months 10 days
Average maturity of debt securities, years			13 years 1 month 9 days
Proceeds from the dispositions of debt securities	$ 59,700,000	773,900,000	$ 155,400,000	943,300,000
Gains from dispositions of debt securities, gross	2,500,000	1,900,000	4,200,000	2,500,000
Losses from dispositions of debt securities, gross	29,000	3,600,000	$ 200,000	4,800,000
Percentage Interest in River Bend			30.00%
Equity Securities, FV-NI, Unrealized Gain	6,000,000		$ 137,200,000
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 375,600,000		$ 375,600,000		367,100,000
Average coupon rate of debt securities	3.09%		3.09%
Average duration of debt securities, years			6 years 10 months 2 days
Average maturity of debt securities, years			9 years 10 months 17 days
Proceeds from the dispositions of debt securities	$ 108,600,000	157,800,000	$ 238,400,000	357,200,000
Gains from dispositions of debt securities, gross	1,700,000	6,500	3,600,000	300,000
Losses from dispositions of debt securities, gross	200,000	$ 300,000	600,000	$ 4,800,000
Equity Securities, FV-NI, Unrealized Gain	2,500,000		91,800,000
Indian Point 3 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	893,000,000		893,000,000		781,000,000
Indian Point 1 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	534,000,000		534,000,000		471,000,000
Indian Point 2 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	676,000,000		676,000,000		598,000,000
Palisades [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	$ 492,000,000		$ 492,000,000		444,000,000
Pilgrim [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value					1,028,000,000	$ 1,030,000,000
Vermont Yankee [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value					$ 532,000,000
Entergy Nuclear Generation Company [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value						$ 1,030,000,000