Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended							9 Months Ended		12 Months Ended
	Jan. 01, 2018	Oct. 31, 2015	Aug. 31, 2008	Jul. 31, 2008	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2016	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2021	Nov. 30, 2019	Jan. 01, 2019
Income Taxes [Line Items]
Valuation allowance on the deferred tax assets related to state net operating loss carryovers						$ 329,000										$ 325,000	$ 329,000
Unrecognized tax benefits if recognized, would lower the effective income tax rates						2,208,000		$ 2,421,000								2,256,000	2,208,000	$ 2,421,000
Remaining balances of unrecognized tax benefits, effective income tax rates						3,491,000		4,962,000								3,504,000	3,491,000	4,962,000
Accrued income tax interest and penalties						44,000		48,000								52,000	44,000	48,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense																8,000		4,000
Deferred Income Taxes and Tax Credits																248,719	(131,114)	193,950
Deferred Tax Assets, Valuation Allowance						328,581										325,239	328,581
Regulatory Liability, Noncurrent						2,323,851										2,643,845	2,323,851
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%																		35.00%	35.00%
Regulatory Liability For Income Taxes - Current and Non Current						1,600,000										1,300,000	1,600,000
Deferred tax asset operating loss carryforward EUHC re-consolidation													$ 41,000
Net operating loss carryforwards						1,580,109										2,868,424	1,580,109
Deferred Tax Assets, Net of Valuation Allowance						4,214,739										4,963,459	4,214,739
Increase (Reduction) in income tax resulting from Entergy Wholesale Commodities restructuring																0	9,223	173,725
Regulatory Liability For Income Taxes Net						1,521,757										1,255,692	1,521,757
Preferred Stock, Value, Issued						0										0	0
Discontinued Operation, Tax Effect of Discontinued Operation									$ 29,000
Permanent difference and income tax benefit		$ 334,000
Reduction in deferred income tax expense																	230,000
Increase in deferred income tax expense																	61,000
Miscellaneous tax benefits																	13,000
Adjustable taxable income limitation	30.00%																							50.00%
Percent of tax group's consolidated assets that consist of regulated utility property																						90.00%
CARES Act Deferred Tax Expense																	64,000
CARES Act annual payroll tax installment due resulting from deferred tax payments																32,000
Reduction in unrecognized tax benefits due to decommissioning liability in COGS																1,500,000
Permanent tax reduction due to stock compensation accounting rules							$ 24,700
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense																	(4,000)
Deferred Income Tax Assets, Net						76,289										54,186	76,289
Deferred Income Tax Liabilities, Net						4,361,772										$ 4,706,797	4,361,772
Limitation on net operating loss carryforwards resulting from Federal CARES Act																80.00%
State of Louisiana Enacted Tax Legislation 2021
Income Taxes [Line Items]
Deferred Income Tax Assets, Net																$ 27,000
Entergy Wholesale Commodities [Member]
Income Taxes [Line Items]
Deferred Income Taxes and Tax Credits																	105,000
Increase in deferred income tax expense																	105,000
Entergy Arkansas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates						259,300		203,300								262,100	259,300	203,300
Accrued income tax interest and penalties						2,300		3,100								2,700	2,300	3,100
Deferred Income Taxes and Tax Credits																100,459	87,019	94,368
Regulatory Liability, Noncurrent						686,872										743,314	686,872
Regulatory Liability For Income Taxes - Current and Non Current						21,000										11,000	21,000
Net operating loss carryforwards						119,555										275,054	119,555
Deferred Tax Assets, Net of Valuation Allowance						554,255										740,723	554,255
Change in accounting method for tax purposes, effect of change on taxable income										$ 1,800,000
Accrued deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements										2,100,000									$ 2,100,000
Regulatory Liability For Income Taxes Net						467,031										$ 431,655	467,031
State Effective Income Tax Rate, Percent												6.50%				6.20%
Permanent tax reduction due to stock compensation accounting rules							4,800
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense																	(800)
Deferred Income Tax Liabilities, Net						1,286,123										$ 1,416,201	1,286,123
Entergy Louisiana [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates						63,800		556,300								66,300	63,800	556,300
Accrued income tax interest and penalties						3,400		14,200								3,700	3,400	14,200
Deferred Income Taxes and Tax Credits																175,700	(356,256)	196,533
Regulatory Liability, Noncurrent						918,293										1,042,597	$ 918,293
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent																	21.00%
Net operating loss carryforwards						363,806										1,228,547	$ 363,806
Deferred Tax Assets, Net of Valuation Allowance						700,307										2,013,578	700,307
Change in accounting method for tax purposes, effect of change on taxable income											$ 2,200,000
Deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements																					$ 2,200,000
Regulatory Liability For Income Taxes Net						447,628										313,693	447,628
Reduction in deferred income tax expense																	383,000
Reduction to income tax expense due to method of accounting																	31,000
Regulatory charge due to prior regulatory settlement - gross																	33,000
Regulatory charge due to prior regulatory settlement - net of tax																	24,000
Increase (Reduction) in income tax resulting from Act 55 financing settlement					$ 32,000		32,000
Reduction of income tax expense due reversal of UTPs					58,000		58,000
Regulatory charge due to LPSC Act 55 Financing Order - Gross					29,000		29,000
Regulatory charge due to LPSC Act 55 Financing Order - Net of Tax					$ 21,000		21,000
Deferred tax liability due to decommissioning liability in COGS																60,000
Decommissioning liability in COGS																221,000
Reduction in unrecognized tax benefits due to decommissioning liability in COGS																1,100,000
Permanent tax reduction due to stock compensation accounting rules							8,600
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense																	(10,800)	(3,700)
Deferred Income Tax Liabilities, Net						2,138,522										$ 2,433,854	2,138,522
Entergy Louisiana [Member] | State of Louisiana Enacted Tax Legislation 2021
Income Taxes [Line Items]
State Effective Income Tax Rate, Percent																8.00%
Reduction in deferred income tax expense																$ 6,000
Increase in state tax rate																0.85%
Deferred Income Tax Liabilities, Net																$ 77,000
Entergy Mississippi [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates						50,700		1,900								51,700	50,700	1,900
Accrued income tax interest and penalties						1,900		1,700								2,400	1,900	1,700
Deferred Income Taxes and Tax Credits																64,868	36,827	32,547
Regulatory Liability, Noncurrent						15,828										49,313	15,828
Net operating loss carryforwards						54,262										166,008	54,262
Deferred Tax Assets, Net of Valuation Allowance						131,887										240,369	131,887
Accrued deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements										$ 1,900,000									$ 1,900,000
Regulatory Liability For Income Taxes Net						224,000										212,445	224,000
Permanent tax reduction due to stock compensation accounting rules							2,700
Deferred Income Tax Liabilities, Net						646,674										720,097	646,674
Entergy New Orleans [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates						203,500		242,700								228,600	203,500	242,700
Accrued income tax interest and penalties						3,900		4,700								5,200	3,900	4,700
Deferred Income Taxes and Tax Credits																12,573	3,938	21,350
Net operating loss carryforwards						26,564										105,549	26,564
Deferred Tax Assets, Net of Valuation Allowance						88,881										155,805	88,881
Reduction to income tax expense																	8,000
Deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements																				$ 1,100,000
Regulatory Liability For Income Taxes Net						55,675										40,589	55,675
Permanent tax reduction due to stock compensation accounting rules							1,500
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense																	(800)
Deferred Income Tax Liabilities, Net						338,714										365,384	338,714
Entergy New Orleans [Member] | State of Louisiana Enacted Tax Legislation 2021
Income Taxes [Line Items]
Reduction in deferred income tax expense																2,000
Deferred Income Tax Liabilities, Net																8,000
Entergy Texas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates						6,100		5,700								2,600	6,100	5,700
Accrued income tax interest and penalties						900		1,100								1,100	900	1,100
Deferred Income Taxes and Tax Credits																48,813	36,033	20,143
Regulatory Liability, Noncurrent						32,297										37,060	32,297
Net operating loss carryforwards						53,052										81	53,052
Deferred Tax Assets, Net of Valuation Allowance						60,543										58,450	60,543
Deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements																	2,500,000
Regulatory Liability For Income Taxes Net						175,594										144,145	175,594
Permanent tax reduction due to stock compensation accounting rules							2,700
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense																	(200)
Deferred Income Tax Liabilities, Net						639,422										692,496	639,422
System Energy [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates						500		0								1,700	500	0
Accrued income tax interest and penalties						11,900		14,500								12,100	11,900	14,500
Deferred Income Taxes and Tax Credits																11,191	(455,732)	$ 95
Regulatory Liability, Noncurrent						665,396										744,944	665,396
Net operating loss carryforwards						0										0	0
Deferred Tax Assets, Net of Valuation Allowance						311,353										347,153	311,353
Change in accounting method for tax purposes, effect of change on taxable income											$ 1,200,000
Regulatory Liability For Income Taxes Net						151,829										113,165	151,829
Deferred tax liability due to decommissioning liability in COGS																26,000
Decommissioning liability in COGS																102,000
Federal and state taxes payable due to decommissioning liability in COGS																402,000
Reduction in unrecognized tax benefits due to decommissioning liability in COGS																461,000
Permanent tax reduction due to stock compensation accounting rules							$ 1,300
Unrecognized Tax Expense, Income Tax Penalties and Interest Expense																	(2,600)
Deferred Income Tax Liabilities, Net						359,835										382,931	359,835
Entergy Wholesale Commodities [Member]
Income Taxes [Line Items]
Increase (Reduction) in income tax resulting from Entergy Wholesale Commodities restructuring						9,200		19,000
Reduction to income tax expense								174,000
Change in accounting method for tax purposes, effect of change on taxable income								$ 18,000
Reduction in unrecognized tax benefits due to decommissioning liability in COGS																							$ 156,000
Hurricane Rita [Member] | Entergy Gulf States Louisiana [Member]
Income Taxes [Line Items]
Proceeds from LURC			$ 274,700
Proceed from loan by LCDA to corporation LURC			$ 274,700
Hurricane Rita [Member] | Entergy Louisiana [Member]
Income Taxes [Line Items]
Proceeds from LURC				$ 679,000
Proceed from loan by LCDA to corporation LURC				$ 679,000
Subsequent Event [Member] | Entergy Arkansas [Member]
Income Taxes [Line Items]
State Effective Income Tax Rate, Percent														5.70%	5.90%
Subsequent Event [Member] | Entergy Louisiana [Member] | State of Louisiana Enacted Tax Legislation 2021
Income Taxes [Line Items]
State Effective Income Tax Rate, Percent															7.50%
Internal Restructuring Guaranteed Credits to Customers [Member]
Income Taxes [Line Items]
Regulatory Liability, Noncurrent						26,400										19,800	26,400
Internal Restructuring Guaranteed Credits to Customers [Member] | Entergy Arkansas [Member]
Income Taxes [Line Items]
Regulatory Liability, Noncurrent						$ 26,400										$ 19,800	$ 26,400
Preferred Stock, Five Point Three Seven Five Percent, Series A [Member] | Entergy Texas [Member]
Income Taxes [Line Items]
Preferred Stock, Value, Issued												$ 35,000	$ 35,000
Preferred Stock, Dividend Rate, Percentage													5.375%
Preferred Stock, Liquidation Preference Per Share												$ 25	$ 25