Retirement, Other Postretirement Benefits, And Defined Contribution Plans (One Percentage Point Change In Assumed Health Care Cost Trend Rate) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
1 Percentage Point Increase, Impact on the APBO	$ 166,814
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	10,221
1 Percentage Point Decrease, Impact on the APBO	(139,648)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	(8,385)
Entergy Arkansas [Member]
1 Percentage Point Increase, Impact on the APBO	23,612
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	1,369
1 Percentage Point Decrease, Impact on the APBO	(19,810)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	(1,133)
Entergy Louisiana [Member]
1 Percentage Point Increase, Impact on the APBO	37,240
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	2,333
1 Percentage Point Decrease, Impact on the APBO	(31,063)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	(1,909)
Entergy Mississippi [Member]
1 Percentage Point Increase, Impact on the APBO	8,666
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	448
1 Percentage Point Decrease, Impact on the APBO	(7,276)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	(370)
Entergy New Orleans [Member]
1 Percentage Point Increase, Impact on the APBO	4,585
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	251
1 Percentage Point Decrease, Impact on the APBO	(3,895)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	(208)
Entergy Texas [Member]
1 Percentage Point Increase, Impact on the APBO	12,444
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	751
1 Percentage Point Decrease, Impact on the APBO	(10,452)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	(618)
System Energy [Member]
1 Percentage Point Increase, Impact on the APBO	7,334
1 Percentage Point Increase, Impact on the sum of service costs and interest cost	475
1 Percentage Point Decrease, Impact on the APBO	(6,074)
1 Percentage Point Decrease, Impact on the sum of service costs and interest cost	$ (387)