Rate And Regulatory Matters (Narrative) (Details)	1 Months Ended												9 Months Ended		12 Months Ended
	Oct. 31, 2017 USD ($)	Aug. 31, 2017	Jul. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	May 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Mar. 31, 2017 $ / kWh	Jan. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Nov. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Apr. 30, 2016	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2016 USD ($)
Regulatory Assets [Line Items]
Impairment of Long-Lived Assets Held-for-use													$ 241,838,000	$ 33,170,000
Payments to Acquire Property, Plant, and Equipment													0	(949,329,000)
Deferred Fuel Cost									$ 108,465,000				185,066,000
Entergy Louisiana [Member]
Regulatory Assets [Line Items]
Payments to Acquire Property, Plant, and Equipment													0	(474,670,000)
Refund To Customers								$ 71,000,000
Earned return on common equity					9.84%
Formula rate plan revenue decrease					$ 16,900,000
Formula rate plan revenue decrease resulting from legacy Entergy Louisiana revenue					3,500,000
Formula rate plan revenue decrease resulting from legacy Entergy Gulf States Louisiana revenue					9,700,000
Formula rate plan revenue decrease resulting from incremental revenue					3,700,000
Adjustment to formula rate plan for reduction in MISO cost recovery mechanism					40,500,000
Current MISO formula rate plan cost recovery													46,800,000
Reduced proposed MISO formula rate plan cost recovery					6,300,000
Authorized return on common equity		9.95%
Earnings bandwidth basis points		16000.00%
Reduced earnings bandwidth basis points		8000.00%
Entergy Mississippi [Member]
Regulatory Assets [Line Items]
Deferred Fuel Cost									6,957,000				34,301,000
Storm Damage Provision			$ 10,000,000
Entergy New Orleans [Member]
Regulatory Assets [Line Items]
Payments to Acquire Property, Plant, and Equipment													0	(237,335,000)
Long-term payable due to Entergy Louisiana									18,423,000				18,423,000
Deferred Fuel Cost									4,818,000				560,000
Energy Smart Program Funding						$ 11,800,000
Proposed customer credits in current year					10,000,000
Proposed customer credits in first quarter of year after transaction closes					1,400,000
Proposed customer credits per month in second year after transaction closes					117,500
Entergy New Orleans [Member] | Subsequent Event [Member]
Regulatory Assets [Line Items]
Proposed customer credits upon FERC approval															$ 5,000,000	$ 5,000,000	$ 5,000,000
Entergy Texas [Member]
Regulatory Assets [Line Items]
Unspecific disallowance associated with settlement agreement									6,000,000
Projected Over-Recovery Balance										$ 21,000,000
Refund for fuel cost recovery				$ 30,700,000
Amount Collected From Customers									29,500,000		$ 29,500,000			10,500,000
Requested increase in retail revenues per request for annual distribution cost recovery factor rider				19,000,000
Amended annual revenue requirement from distribution cost recovery factor rider			18,300,000
Estimated nominal benefit to Customers Anticipated with AMI Deployment			33,000,000
Book Value of Existing Meters to be Retired with AMI Deployment									41,000,000
Current annual collection from distribution cost recovery factor rider				$ 8,650,000
Entergy Arkansas [Member]
Regulatory Assets [Line Items]
Payments to Acquire Property, Plant, and Equipment													0	$ (237,324,000)
Deferred Fuel Cost									$ 96,690,000				$ 150,206,000
Rate At Which Electricity Sold To Retail Customers | $ / kWh							0.01164
Increase in Rate At Which Electricity Sold To Retail Customers | $ / kWh							0.01547
Projected Increase in Revenue Requirement			$ 129,700,000
Earned return on common equity			9.75%
Annual revenue constraint per rate class percentage			400.00%
Reduced requested increase in revenue requirement to comply with annual revenue constraint			$ 70,900,000
ALJ Recommended Percentage By Which Payments Be Reduced												20.00%
Payments due Utility Operating Companies Related to Opportunity Sales Proceedings			$ 86,000,000
Liability Recorded Related to Estimated Payments Due Utility Operating Companies																		$ 87,000,000
Regulatory Asset Recorded to Represent Estimate of Recoverable Retail Portion of Costs																		$ 75,000,000
Entergy Arkansas [Member] | Subsequent Event [Member]
Regulatory Assets [Line Items]
Projected Increase in Revenue Requirement	$ 126,200,000
Reduced requested increase in revenue requirement to comply with annual revenue constraint	$ 71,100,000
System Energy [Member]
Regulatory Assets [Line Items]
Earned return on common equity													10.94%
System Energy [Member] | Minimum [Member]
Regulatory Assets [Line Items]
Recommended adjustment to earned return on equity								8.37%
System Energy [Member] | Maximum [Member]
Regulatory Assets [Line Items]
Recommended adjustment to earned return on equity								8.67%
Natural Gas Processing Plant [Member] | Entergy Louisiana [Member]
Regulatory Assets [Line Items]
Earned return on common equity								6.37%
Requested Recovery of Previously Deferred Operation and Maintenance Expenses					1,400,000			$ 1,500,000
Recommended recovery of previously deferred operation and maintenance expenses					$ 900,000
Public Utilities, Requested Increase in Revenue Requirement						$ 1,200,000		$ 1,400,000