Retirement And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2020
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 216,300
Defined Benefit Plan, Plan Assets, Contributions by Employer	59,800
Entergy Arkansas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	32,512
Defined Benefit Plan, Plan Assets, Contributions by Employer	10,120
Entergy Louisiana [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	38,766
Defined Benefit Plan, Plan Assets, Contributions by Employer	8,676
Entergy Mississippi [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	7,768
Defined Benefit Plan, Plan Assets, Contributions by Employer	2,560
Entergy New Orleans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	3,248
Defined Benefit Plan, Plan Assets, Contributions by Employer	563
Entergy Texas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	3,549
Defined Benefit Plan, Plan Assets, Contributions by Employer	453
System Energy [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	10,544
Defined Benefit Plan, Plan Assets, Contributions by Employer	3,299
Subsequent Event [Member] | Entergy Arkansas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 22,392
Subsequent Event [Member] | Entergy Louisiana [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			30,090
Subsequent Event [Member] | Entergy Mississippi [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			5,208
Subsequent Event [Member] | Entergy New Orleans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			2,685
Subsequent Event [Member] | Entergy Texas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			3,096
Subsequent Event [Member] | System Energy [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 7,245
Non Qualified Pension Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	4,500	$ 4,000
Non Qualified Pension Plans [Member] | Entergy Arkansas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	83	73
Non Qualified Pension Plans [Member] | Entergy Louisiana [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	37	43
Non Qualified Pension Plans [Member] | Entergy Mississippi [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	90	75
Non Qualified Pension Plans [Member] | Entergy New Orleans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	8	5
Non Qualified Pension Plans [Member] | Entergy Texas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	$ 117	$ 124