Retirement And Other Postretirement Benefits (Expected Employer Contributions) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	$ 84,200
Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		$ 409,900
Entergy Louisiana [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	17,591
Entergy Louisiana [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		87,923
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		70,332
Entergy Mississippi [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	4,027
Entergy Mississippi [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		19,146
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		15,119
Entergy New Orleans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	2,273
Entergy New Orleans [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		9,920
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		7,647
Entergy Texas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	3,294
Entergy Texas [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		17,064
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		13,770
System Energy [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	4,500
System Energy [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		18,180
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		13,680
Entergy Arkansas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	$ 17,265
Entergy Arkansas [Member] | Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year		79,495
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		$ 62,230