Income Taxes (Significant Components Of Accumulated Deferred Income Taxes And Taxes Accrued) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Plant basis differences - net	$ (4,795,422)	$ (4,111,761)
Regulatory assets for income taxes - net	(429,996)	(389,573)
Nuclear decommissioning trusts	(1,188,235)	(1,015,542)
Pension, net funding	(327,445)	(348,260)
Combined unitary state taxes	(7,723)	(11,519)
Deferred Tax Liability, Deferred Fuel	(7,667)	(8,360)
Other	(549,355)	(445,378)
Total	(7,314,995)	(6,340,611)
Regulatory liabilities	791,927	806,777
Pension and other post-employment benefits	278,486	297,272
Sale and leaseback	102,477	102,420
Compensation	89,279	87,355
Accumulated deferred investment tax credit	57,379	56,013
Provision for allowances and contingencies	71,598	126,886
Deferred Tax Assets, Power Purchase Arrangements	352,019	231,502
Net operating loss carryforwards	1,580,109	1,133,197
Capital losses and miscellaneous tax credits	21,291	22,597
Valuation allowance	(328,581)	(303,307)
Other	230,291	289,557
Deferred Tax Assets, Net of Valuation Allowance	4,214,739	3,779,520
Non-current accrued taxes (including unrecognized tax benefits)	(1,185,227)	(1,775,638)
Deferred Tax Liabilities, Deferred Expense	(9,152)	(10,218)
Deferred tax asset Nuclear Decommissioning Liabilities	968,464	929,251
Deferred Tax Liabilities, Net, Noncurrent	(4,285,483)	(4,336,729)
Entergy Arkansas [Member]
Plant basis differences - net	(1,117,948)	(979,033)
Regulatory assets for income taxes - net	(188,284)	(170,949)
Nuclear decommissioning trusts	(156,123)	(120,306)
Pension, net funding	(93,486)	(102,685)
Deferred fuel	0	0
Other	(54,753)	(82,682)
Total	(1,610,594)	(1,455,655)
Regulatory liabilities	273,774	250,410
Deferred tax Liability, Accrued Tax Expense, Compensation and Benefits Pensions	(24,747)	(21,828)
Sale and leaseback	0	0
Compensation	2,264	2,550
Accumulated deferred investment tax credit	7,971	8,285
Provision for allowances and contingencies	22,179	5,365
Deferred Tax Assets, Power Purchase Arrangements	9,662	(15,087)
Net operating loss carryforwards	119,555	112,658
Other	16,036	12,541
Deferred Tax Assets, Net of Valuation Allowance	554,255	471,869
Accrued Income Taxes, Noncurrent	229,784	199,340
Deferred Tax Assets, Deferred Income	4,242	5,897
Deferred Tax Assets, Capital Losses and Miscellaneous Tax Credits	0	0
Deferred tax asset Nuclear Decommissioning Liabilities	123,319	111,078
Deferred Tax Liabilities, Net, Noncurrent	(1,286,123)	(1,183,126)
Entergy Louisiana [Member]
Plant basis differences - net	(2,481,976)	(1,987,025)
Regulatory assets for income taxes - net	(95,135)	(79,117)
Nuclear decommissioning trusts	(148,040)	(113,830)
Pension, net funding	(95,854)	(98,743)
Deferred fuel	(4,210)	(2,637)
Other	(76,735)	(94,139)
Total	(2,901,950)	(2,375,491)
Regulatory liabilities	218,278	283,507
Pension and other post-employment benefits	72,724	74,881
Sale and leaseback	0	0
Compensation	3,240	3,670
Accumulated deferred investment tax credit	31,155	32,534
Provision for allowances and contingencies	7,071	77,298
Deferred Tax Assets, Power Purchase Arrangements	3,381	18,004
Net operating loss carryforwards	363,806	65,178
Other	6,958	35,401
Deferred Tax Assets, Net of Valuation Allowance	700,307	618,692
Deferred Tax Liabilities, Prepaid Expenses	63,121
Accrued Income Taxes, Noncurrent		707,714
Deferred Tax Liabilities, Deferred Expense	(23,382)	(28,081)
Deferred Tax Assets, Capital Losses and Miscellaneous Tax Credits	9,309	0
Deferred tax asset Nuclear Decommissioning Liabilities	7,767	56,300
Deferred Tax Liabilities, Net, Noncurrent	(2,138,522)	(2,464,513)
Entergy Mississippi [Member]
Plant basis differences - net	(623,796)	(565,202)
Regulatory assets for income taxes - net	(22,381)	(10,528)
Nuclear decommissioning trusts	0	0
Pension, net funding	(24,922)	(27,325)
Deferred fuel	(1,706)	(609)
Other	(27,565)	(27,905)
Total	(700,370)	(631,569)
Regulatory liabilities	56,022	53,421
Deferred tax Liability, Accrued Tax Expense, Compensation and Benefits Pensions	(6,763)	(5,844)
Sale and leaseback	0	0
Compensation	1,670	1,625
Accumulated deferred investment tax credit	2,261	2,396
Provision for allowances and contingencies	16,799	12,963
Deferred Tax Assets, Power Purchase Arrangements	1,140	1,147
Net operating loss carryforwards	54,262	21,492
Other	3,507	999
Deferred Tax Assets, Net of Valuation Allowance	131,887	92,959
Accrued Income Taxes, Noncurrent	78,191	56,222
Deferred Tax Assets, Deferred Income	2,989	4,715
Deferred Tax Assets, Capital Losses and Miscellaneous Tax Credits	0	45
Deferred tax asset Nuclear Decommissioning Liabilities	0	0
Deferred Tax Liabilities, Net, Noncurrent	(646,674)	(594,832)
Entergy New Orleans [Member]
Plant basis differences - net	(83,457)	(133,073)
Regulatory assets for income taxes - net	(20,276)	(16,867)
Nuclear decommissioning trusts	0	0
Pension, net funding	(11,564)	(11,859)
Deferred fuel	(1,393)	(666)
Other	(26,334)	(25,909)
Total	(143,024)	(188,374)
Regulatory liabilities	31,248	33,258
Deferred tax Liability, Accrued Tax Expense, Compensation and Benefits Pensions	(13,997)	(12,666)
Sale and leaseback	0	0
Compensation	761	496
Accumulated deferred investment tax credit	4,197	556
Provision for allowances and contingencies	24,529	24,022
Deferred Tax Assets, Power Purchase Arrangements	(5,324)	7,961
Net operating loss carryforwards	26,564	5,056
Other	8,128	9,027
Deferred Tax Assets, Net of Valuation Allowance	88,881	69,138
Accrued Income Taxes, Noncurrent	284,571	235,300
Deferred Tax Assets, Deferred Income	877	1,428
Deferred Tax Assets, Capital Losses and Miscellaneous Tax Credits	12,317	0
Deferred tax asset Nuclear Decommissioning Liabilities	(419)	0
Deferred Tax Liabilities, Net, Noncurrent	(338,714)	(354,536)
Entergy Texas [Member]
Plant basis differences - net	(620,669)	(551,365)
Regulatory assets for income taxes - net	(47,684)	(59,745)
Nuclear decommissioning trusts	0	0
Pension, net funding	(19,481)	(19,961)
Deferred fuel	0	(4,380)
Other	(141)	2,059
Total	(687,975)	(633,392)
Regulatory liabilities	47,991	65,602
Deferred tax Liability, Accrued Tax Expense, Compensation and Benefits Pensions	(17,132)	(15,406)
Sale and leaseback	0	0
Compensation	1,308	1,282
Accumulated deferred investment tax credit	2,088	2,217
Deferred Tax Liabilities, Deferred Expense, Reserves and Accruals	4,094
Provision for allowances and contingencies		4,024
Deferred Tax Assets, Power Purchase Arrangements	(30,932)	26
Net operating loss carryforwards	53,052	0
Other	2,232	2,004
Deferred Tax Assets, Net of Valuation Allowance	60,543	65,293
Accrued Income Taxes, Noncurrent	11,990	17,314
Deferred Tax Assets, Deferred Income	5,909	5,544
Deferred Tax Assets, Capital Losses and Miscellaneous Tax Credits	0	0
Deferred tax asset Nuclear Decommissioning Liabilities	121	0
Deferred Tax Liabilities, Net, Noncurrent	(639,422)	(585,413)
System Energy [Member]
Plant basis differences - net	(407,125)	(380,594)
Regulatory assets for income taxes - net	(56,496)	(52,662)
Nuclear decommissioning trusts	(131,985)	(100,621)
Pension, net funding	(20,330)	(21,609)
Deferred fuel	(314)	(55)
Other	(12,521)	(7,350)
Total	(628,771)	(562,891)
Regulatory liabilities	163,534	121,011
Deferred tax Liability, Accrued Tax Expense, Compensation and Benefits Pensions	(1,344)	(898)
Sale and leaseback	102,477	102,480
Compensation	48	75
Accumulated deferred investment tax credit	9,706	10,025
Provision for allowances and contingencies	0	0
Deferred Tax Assets, Power Purchase Arrangements	0	0
Net operating loss carryforwards	0	0
Other	2	3
Deferred Tax Assets, Net of Valuation Allowance	311,353	293,186
Accrued Income Taxes, Noncurrent	42,417	544,235
Deferred Tax Assets, Deferred Income	0	0
Deferred Tax Assets, Capital Losses and Miscellaneous Tax Credits	7,014	7,857
Deferred tax asset Nuclear Decommissioning Liabilities	29,916	52,633
Deferred Tax Liabilities, Net, Noncurrent	$ (359,835)	$ (813,940)