Asset Retirement Obligations (Cumulative Decommissioning And Retirement Cost Liabilities And Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Entergy Arkansas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	$ 818.4	$ 723.8
Accretion	50.4	47.0
Change in Cash Flow Estimate	0.0	47.6
Spending	0.0	0.0
Liabilities	872.3	818.4
Asset Retirement Obligation, Liabilities Incurred	3.5
Entergy Louisiana [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	950.3	882.2
Accretion	51.0	48.1
Change in Cash Flow Estimate	24.7	20.0
Spending	0.0	0.0
Liabilities	1,027.9	950.3
Asset Retirement Obligation, Liabilities Incurred	1.9
Entergy Mississippi [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	6.8	6.4
Accretion	0.4	0.4
Change in Cash Flow Estimate	0.0	0.0
Spending	0.0	0.0
Liabilities	8.3	6.8
Asset Retirement Obligation, Liabilities Incurred	1.1
Entergy New Orleans [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	2.5	2.3
Accretion	0.2	0.2
Change in Cash Flow Estimate	0.0	0.0
Spending	0.0	0.0
Liabilities	2.7	2.5
Asset Retirement Obligation, Liabilities Incurred	0.0
Entergy Texas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	4.6	4.3
Accretion	0.3	0.3
Change in Cash Flow Estimate	(0.2)	0.0
Spending	0.0	0.0
Liabilities	6.1	4.6
Asset Retirement Obligation, Liabilities Incurred	1.4
System Energy [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	757.9	616.2
Accretion	48.0	41.8
Change in Cash Flow Estimate	(2.5)	99.9
Spending	0.0	0.0
Liabilities	803.4	757.9
Asset Retirement Obligation, Liabilities Incurred	0.0
Entergy Wholesale Commodities [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	1,917.8	1,698.2
Accretion	153.8	139.7
Change in Cash Flow Estimate	99.6	101.6
Spending	(101.7)	(21.7)
Liabilities	2,069.5	$ 1,917.8
Asset Retirement Obligation, Liabilities Incurred	$ 0.0

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Asset Retirement Obligation
-URI http://asc.fasb.org/extlink&oid=6505190

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

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Amount of asset retirement obligations incurred during the period.

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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

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Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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