Retirement And Other Postretirement Benefits (Expected Employer Contributions) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2020	Sep. 30, 2020
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		$ 416,300
Defined Benefit Plan, Plan Assets, Contributions by Employer		189,500
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		74,572
Defined Benefit Plan, Plan Assets, Contributions by Employer		30,988
Entergy Louisiana [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 43,584
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		15,664
Defined Benefit Plan, Plan Assets, Contributions by Employer		8,691
Entergy Mississippi [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer	6,973
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		6,301
Defined Benefit Plan, Plan Assets, Contributions by Employer		2,353
Entergy New Orleans [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer	3,948
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		6,901
Defined Benefit Plan, Plan Assets, Contributions by Employer		2,517
Entergy Texas [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer	4,384
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		20,406
Defined Benefit Plan, Plan Assets, Contributions by Employer		10,635
System Energy [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer	9,771
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		73,905
Defined Benefit Plan, Plan Assets, Contributions by Employer		$ 43,032
Entergy Arkansas [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 30,873