Asset Retirement Obligations (Cumulative Decommissioning And Retirement Cost Liabilities And Expenses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Entergy Arkansas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	$ 723.8	$ 680.7
Accretion	47.0	43.1
Change in Cash Flow Estimate	47.6
Liabilities	818.4	723.8
Entergy Gulf States Louisiana [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	403.1	380.8
Accretion	23.5	22.3
Change in Cash Flow Estimate	20.0
Liabilities	446.6	403.1
Entergy Louisiana [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	479.1	418.1
Accretion	24.6	21.6
Change in Cash Flow Estimate	0	39.4
Liabilities	503.7	479.1
Entergy Mississippi [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	6.4	6.0
Accretion	0.4	0.4
Liabilities	6.8	6.4
Entergy New Orleans [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	2.3	2.2
Accretion	0.2	0.1
Liabilities	2.5	2.3
Entergy Texas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	4.3	4.1
Accretion	0.3	0.2
Liabilities	4.6	4.3
System Energy [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	616.2	478.4
Accretion	41.8	35.5
Change in Cash Flow Estimate	99.9	102.3
Liabilities	757.9	616.2
Entergy Wholesale Commodities [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities	1,698.2	1,543.3
Accretion	139.7	125.3
Change in Cash Flow Estimate	101.6	38.6
Spending	(21.7)	(9.0)
Liabilities	$ 1,917.8	$ 1,698.2

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 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

Reference 2: 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

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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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