Decommissioning Trust Funds (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	May 28, 2021
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts	$ (1,259,000)	$ (1,513,000)	$ (26,867,000)	$ 18,042,000
Amortized cost of debt securities	$ 1,992,000,000		$ 1,992,000,000		$ 2,423,000,000
Average coupon rate of debt securities	2.73%		2.73%
Average duration of debt securities, years			6 years 9 months 3 days
Average maturity of debt securities, years			10 years 4 months 9 days
Proceeds from the dispositions of debt securities	$ 354,000,000	156,000,000	$ 1,151,000,000	832,000,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	300,000		300,000		100,000
Equity Securities, FV-NI, Unrealized Gain			359,000,000
Equity Securities, FV-NI, Unrealized Loss	(22,000,000)
Debt Securities, Available-for-sale, Realized Gain	8,000,000	9,000,000	24,000,000	38,000,000
Debt Securities, Available-for-sale, Realized Loss	2,000,000	200,000	15,000,000	4,000,000
Debt Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts			4,000,000		31,000,000
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 468,000,000		$ 468,000,000		420,400,000
Average coupon rate of debt securities	2.26%		2.26%
Average duration of debt securities, years			6 years 1 month 6 days
Average maturity of debt securities, years			7 years 1 month 28 days
Proceeds from the dispositions of debt securities	$ 20,600,000	14,600,000	$ 46,700,000	80,900,000
Equity Securities, FV-NI, Unrealized Gain			93,900,000
Equity Securities, FV-NI, Unrealized Loss	(8,000,000)
Debt Securities, Available-for-sale, Realized Gain	700,000	1,700,000	2,300,000	7,500,000
Debt Securities, Available-for-sale, Realized Loss	200,000	3,600	300,000	200,000
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 676,000,000		$ 676,000,000		581,400,000
Average coupon rate of debt securities	3.42%		3.42%
Average duration of debt securities, years			6 years 8 months 26 days
Average maturity of debt securities, years			12 years 3 months 14 days
Proceeds from the dispositions of debt securities	$ 20,500,000	30,600,000	$ 191,400,000	132,100,000
Percentage Interest in River Bend			30.00%
Equity Securities, FV-NI, Unrealized Gain			$ 150,600,000
Equity Securities, FV-NI, Unrealized Loss	(6,700,000)
Debt Securities, Available-for-sale, Realized Gain	900,000	1,400,000	5,600,000	6,300,000
Debt Securities, Available-for-sale, Realized Loss	23,500	1,300	3,400,000	700,000
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 458,000,000		$ 458,000,000		398,400,000
Average coupon rate of debt securities	2.28%		2.28%
Average duration of debt securities, years			7 years 2 months 4 days
Average maturity of debt securities, years			10 years 2 months 4 days
Proceeds from the dispositions of debt securities	$ 292,800,000	24,100,000	$ 468,500,000	189,700,000
Equity Securities, FV-NI, Unrealized Gain			96,100,000
Equity Securities, FV-NI, Unrealized Loss	(7,100,000)
Debt Securities, Available-for-sale, Realized Gain	5,900,000	1,600,000	9,000,000	8,600,000
Debt Securities, Available-for-sale, Realized Loss	2,000,000	$ 9,900	3,800,000	$ 400,000
Indian Point 3 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value					991,000,000
Indian Point 1 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value					631,000,000
Indian Point 2 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value					794,000,000
Palisades [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	$ 562,000,000		$ 562,000,000		$ 554,000,000
Entergy Wholesale Commodities [Member] | Indian Point Energy Center
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value						$ 2,387,000,000