Retirement And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		$ 25,000		$ 46,000	$ 108,000	$ 71,000	$ 148,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 159,700
Entergy Arkansas [Member]
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		3,600		6,400	13,700	13,400	30,700
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			29,453
Entergy Louisiana [Member]
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		6,200		12,300	27,800	26,100	50,700
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			33,066
Entergy Mississippi [Member]
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		500		1,100	2,700	2,400	6,300
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			6,924
Entergy New Orleans [Member]
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		200		400	1,300	1,000	4,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			3,373
Entergy Texas [Member]
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		14		(200)	200	(1,100)	4,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			5,433
System Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		2,300		3,300	$ 6,200	$ 5,100	$ 10,200
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Plan Assets, Contributions by Employer			6,349
Subsequent Event [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year								$ 352,100
Subsequent Event [Member] | 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								64,062
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year								34,609
Subsequent Event [Member] | 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								71,917
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year								38,851
Subsequent Event [Member] | 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								14,933
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year								8,009
Subsequent Event [Member] | 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								7,250
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year								3,877
Subsequent Event [Member] | 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								10,883
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year								5,450
Subsequent Event [Member] | 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								13,786
Defined Benefit Plan Remaining Contributions To Be Made In Current Fiscal Year								$ 7,437
Non Qualified Pension Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	$ 6,600	8,500	15,500	13,100
Settlement Charge Associated With Out Of Plan Payment Of Lump Sum Benefits	2,400	4,000	6,800	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	122	267	254	372
Settlement Charge Associated With Out Of Plan Payment Of Lump Sum Benefits	10	163	22	163
Non Qualified Pension Plans [Member] | Entergy Louisiana [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	46	47	96	96
Non Qualified Pension Plans [Member] | Entergy Mississippi [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	77	63	157	127
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	21	18	42	36
Non Qualified Pension Plans [Member] | Entergy Texas [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Net periodic benefit costs	270	$ 126	407	$ 253
Settlement Charge Associated With Out Of Plan Payment Of Lump Sum Benefits	$ 139		$ 139