Rate And Regulatory Matters (Narrative) (Details)	1 Months Ended							3 Months Ended
	May 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Mar. 31, 2017 USD ($) $ / kWh	Jan. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Nov. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)
Regulatory Assets [Line Items]
Impairment of Long-Lived Assets Held-for-use								$ 145,026,000	$ 7,361,000
Payments to Acquire Property, Plant, and Equipment								0	(947,778,000)
Deferred Fuel Cost			$ 117,971,000		$ 108,465,000			117,971,000
Entergy Louisiana [Member]
Regulatory Assets [Line Items]
Payments to Acquire Property, Plant, and Equipment								0	(473,888,000)
Refund To Customers				$ 71,000,000
Entergy Mississippi [Member]
Regulatory Assets [Line Items]
Deferred Fuel Cost			12,193,000		6,957,000			12,193,000
Entergy New Orleans [Member]
Regulatory Assets [Line Items]
Payments to Acquire Property, Plant, and Equipment								0	(236,944,000)
Long-term payable due to Entergy Louisiana			18,423,000		18,423,000			18,423,000
Deferred Fuel Cost			0		4,818,000			0
Entergy New Orleans [Member] | Subsequent Event [Member]
Regulatory Assets [Line Items]
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
Proposed customer credits upon FERC approval	$ 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
Amount Collected From Customers					29,500,000		$ 29,500,000	10,500,000
Entergy Arkansas [Member]
Regulatory Assets [Line Items]
Payments to Acquire Property, Plant, and Equipment								0	$ (236,947,000)
Deferred Fuel Cost			$ 105,778,000		$ 96,690,000			$ 105,778,000
Rate At Which Electricity Sold To Retail Customers | $ / kWh			0.01164
Increase in Rate At Which Electricity Sold To Retail Customers | $ / kWh			0.01547
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				$ 1,500,000
Public Utilities, Requested Increase in Revenue Requirement				$ 1,400,000
Natural Gas Processing Plant [Member] | Entergy Louisiana [Member] | Subsequent Event [Member]
Regulatory Assets [Line Items]
Public Utilities, Requested Increase in Revenue Requirement		$ 1,200,000