Retirement And Other Postretirement Benefits (Expected Employer Contributions) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	$ 318,000
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	67,993
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		86,728
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		18,735
Entergy Mississippi [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	14,922
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		19,063
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		4,141
Entergy New Orleans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	7,832
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		9,842
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		2,010
Entergy Texas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	13,131
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		16,908
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		3,777
System Energy [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	14,498
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		18,307
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		3,809
Entergy Arkansas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	$ 62,252
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		79,725
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year		$ 17,473