Retirement, Other Postretirement Benefits, And Defined Contribution Plans Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Concentration Risk		10.00%
Change in Plan Assets
non-current pension liability		$ 2,853,013	$ 2,798,265
Current pension liability		61,815	66,184
Defined Benefit Plan, Plan Assets, Payment for Settlement		(84,754)	(68,203)
Non-Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		161,300	143,400
Net periodic benefit costs		18,100	22,600	$ 24,400
Settlement charges related to the payment of lump sum benefits out of the plan			7,400	7,700
Projected benefit obligation		182,400	162,800
Defined Benefit Plan Benefit Obligation, Current		22,900	18,100
Defined Benefit Plan Benefit Obligation, Non-Current		159,500	144,600
Amortization of prior service credit		77,300	58,800
Accumulated other comprehensive income (before taxes)		16,700	24,900
Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		6,854,426	6,271,160	5,497,415
Change in Plan Assets
Projected benefit obligation		9,143,652	8,406,203	7,404,917
non-current pension liability		2,289,226	2,135,043
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		6,854,426	6,271,160
Change in Plan Assets
Accumulated pension benefit obligation		8,400,000	7,800,000
Net periodic benefit costs		373,784	276,969	255,613
Amortization of prior service credit		0	0	398
Expected Employer Contributions		356,000
Defined Contribution Plans [Member]
Change in Plan Assets
Subsidiaries' contribution to defined contribution plan		$ 63,100	57,600	54,300
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		6.00%
Defined Contribution Plans [Member] | Subsequent Event [Member]
Change in Plan Assets
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	500.00%
Defined Contribution Plan Discretionary Employer Matching Contribution Percent	400.00%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		$ 737,866	686,262	609,782
Change in Plan Assets
Net periodic benefit costs		(17,184)	(5,593)	13,088
Projected benefit obligation		1,181,075	1,252,903	1,232,619
non-current pension liability		404,246	518,601
Current pension liability		38,963	48,040
Amortization of prior service credit		(32,882)	(35,377)	(37,002)
Accumulated other comprehensive income (before taxes)		(59,216)	(37,901)
Expected Employer Contributions		39,900
Entergy Arkansas [Member]
Change in Plan Assets
non-current pension liability		361,682	319,075
Defined Benefit Plan, Plan Assets, Payment for Settlement		(48,400)
Entergy Arkansas [Member] | Non-Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		2,626	2,248
Net periodic benefit costs		333	275	474
Projected benefit obligation		3,197	2,755
non-current pension liability		2,979	2,506
Current pension liability		218	249
Accumulated other comprehensive income (before taxes)		0
Settlement charges			30
Entergy Arkansas [Member] | Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		1,285,856	1,200,035	1,068,842
Change in Plan Assets
Projected benefit obligation		1,739,382	1,615,084	1,443,808
non-current pension liability		453,526	415,049
Entergy Arkansas [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		1,617,858	1,519,998
Net periodic benefit costs		81,723	44,400	43,020
Entergy Arkansas [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		304,192	284,224	252,055
Change in Plan Assets
Net periodic benefit costs		(10,075)	(10,747)	(10,168)
Projected benefit obligation		209,369	185,744	187,830
Current pension liability		0	0
Amortization of prior service credit		(1,849)	(4,950)	(5,110)
Accumulated other comprehensive income (before taxes)		0	0
Expected Employer Contributions		517
Entergy Louisiana [Member]
Change in Plan Assets
non-current pension liability		692,728	677,619
Defined Benefit Plan, Plan Assets, Payment for Settlement		(18,600)
Entergy Louisiana [Member] | Non-Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		1,802	1,682
Net periodic benefit costs		148	159	180
Projected benefit obligation		1,965	1,682
non-current pension liability		1,772	1,467
Current pension liability		193	216
Accumulated other comprehensive income (before taxes)		18
Entergy Louisiana [Member] | Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		1,476,306	1,364,030	1,215,926
Change in Plan Assets
Projected benefit obligation		1,927,271	1,784,474	1,599,916
non-current pension liability		450,965	420,444
Entergy Louisiana [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		1,753,980	1,643,759
Net periodic benefit costs		70,648	48,630	52,108
Entergy Louisiana [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		0	0	0
Change in Plan Assets
Net periodic benefit costs		5,583	7,259	11,194
Projected benefit obligation		255,571	274,175	275,269
non-current pension liability		239,991	255,708
Current pension liability		15,580	18,467
Amortization of prior service credit		(6,179)	(7,349)	(7,735)
Accumulated other comprehensive income (before taxes)		(37,792)	(29,654)
Expected Employer Contributions		15,600
Entergy Mississippi [Member]
Change in Plan Assets
non-current pension liability		110,901	99,406
Defined Benefit Plan, Plan Assets, Payment for Settlement		(7,700)
Entergy Mississippi [Member] | Non-Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		3,345	2,938
Net periodic benefit costs		359	326	300
Projected benefit obligation		3,852	3,286
non-current pension liability		3,671	2,930
Current pension liability		181	357
Accumulated other comprehensive income (before taxes)		0
Settlement charges			40
Entergy Mississippi [Member] | Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		371,394	354,928	316,716
Change in Plan Assets
Projected benefit obligation		510,109	471,510	414,089
non-current pension liability		138,715	116,582
Entergy Mississippi [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		466,497	438,817
Net periodic benefit costs		20,184	11,331	10,792
Entergy Mississippi [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		93,475	86,085	75,853
Change in Plan Assets
Net periodic benefit costs		(3,644)	(2,100)	(1,513)
Projected benefit obligation		61,990	65,979	68,976
Current pension liability		0	0
Amortization of prior service credit		(1,652)	(1,756)	(1,823)
Accumulated other comprehensive income (before taxes)		0	0
Expected Employer Contributions		130
Entergy New Orleans [Member] | Non-Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		240	230
Net periodic benefit costs		31	20	81
Projected benefit obligation		247	231
non-current pension liability		230	215
Current pension liability		17	17
Accumulated other comprehensive income (before taxes)		0
Entergy New Orleans [Member] | Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		172,551	160,777	145,968
Change in Plan Assets
Projected benefit obligation		220,287	206,962	191,190
non-current pension liability		47,736	46,185
Entergy New Orleans [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		201,159	192,561
Net periodic benefit costs		5,988	5,101	5,789
Entergy New Orleans [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		102,734	93,858	81,774
Change in Plan Assets
Net periodic benefit costs		(4,929)	(3,450)	(3,673)
Projected benefit obligation		31,707	38,460	41,987
Current pension liability		0	0
Amortization of prior service credit		(763)	(682)	(745)
Accumulated other comprehensive income (before taxes)		0	0
Expected Employer Contributions		175
Entergy Texas [Member]
Change in Plan Assets
Defined Benefit Plan, Plan Assets, Payment for Settlement		(9,800)
Difference between rate case pension amounts and actuarially determined pension amounts		3,800
Entergy Texas [Member] | Non-Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		7,949	7,391
Net periodic benefit costs		469	481	650
Projected benefit obligation		8,475	7,783
non-current pension liability		7,842	7,060
Current pension liability		633	723
Accumulated other comprehensive income (before taxes)		0
Settlement charges			139
Entergy Texas [Member] | Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		349,748	339,126	315,514
Change in Plan Assets
Projected benefit obligation		410,664	396,764	369,604
non-current pension liability		60,916	57,638
Entergy Texas [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		379,050	371,589
Net periodic benefit costs		12,358	5,740	4,158
Entergy Texas [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		174,096	161,810	144,846
Change in Plan Assets
Net periodic benefit costs		(8,873)	(6,503)	(6,204)
Projected benefit obligation		74,233	94,742	88,310
Current pension liability		0	0
Amortization of prior service credit		(3,364)	(2,243)	(2,316)
Accumulated other comprehensive income (before taxes)		0	0
Expected Employer Contributions		66
System Energy [Member]
Change in Plan Assets
non-current pension liability		125,412	109,816
Defined Benefit Plan, Plan Assets, Payment for Settlement		(236)
System Energy [Member] | Qualified Pension Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		310,818	282,668	245,516
Change in Plan Assets
Projected benefit obligation		441,148	393,607	339,034
non-current pension liability		130,330	110,939
System Energy [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Accumulated pension benefit obligation		410,296	368,771
Net periodic benefit costs		17,341	12,345	14,905
System Energy [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount		52,619	48,471	43,670
Change in Plan Assets
Net periodic benefit costs		(1,518)	(1,009)	(490)
Projected benefit obligation		47,701	47,348	48,791
Current pension liability		0	0
Amortization of prior service credit		(1,065)	(1,450)	$ (1,513)
Accumulated other comprehensive income (before taxes)		0	$ 0
Expected Employer Contributions		$ 22
Minimum [Member] | Defined Contribution Plans [Member]
Change in Plan Assets
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		70.00%
Maximum [Member] | Defined Contribution Plans [Member]
Change in Plan Assets
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		100.00%
Maximum [Member] | Defined Contribution Plans [Member] | Subsequent Event [Member]
Change in Plan Assets
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Domestic Equity Securities [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		39.00%
Domestic Equity Securities [Member] | Minimum [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		32.00%
Domestic Equity Securities [Member] | Maximum [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		46.00%
International Equity Securities [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		19.00%
International Equity Securities [Member] | Minimum [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		15.00%
International Equity Securities [Member] | Maximum [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		23.00%
Fixed Income Securities [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		42.00%
Fixed Income Securities [Member] | Minimum [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		39.00%
Fixed Income Securities [Member] | Maximum [Member] | Qualified Pension Plans [Member]
Change in Plan Assets
Target asset allocation		45.00%