Asset Retirement Obligations (Cumulative Decommissioning And Retirement Cost Liabilities And Expenses) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		$ 6,923.4	$ 6,185.8	$ 6,706.8
Accretion		423.5	431.5
Change in Cash Flow Estimate		505.4	(104.6)
Spending	$ (727.3)	(191.3)	(120.6)
Entergy Arkansas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		1,048.4	981.2	924.4
Accretion		60.4	56.8
Change in Cash Flow Estimate		8.9	0.0
Spending		(2.1)	0.0
Entergy Louisiana [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		1,280.3	1,140.5	1,082.7
Accretion		63.2	57.8
Change in Cash Flow Estimate		85.4	0.0
Spending		(8.8)	0.0
Entergy Mississippi [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		9.2	9.2	8.7
Accretion		0.5	0.5
Change in Cash Flow Estimate		0.5	0.0
Spending		(1.0)	0.0
Entergy New Orleans [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		3.3	3.1	2.9
Accretion		0.2	0.2
Change in Cash Flow Estimate		0.0	0.0
Spending		0.0	0.0
Entergy Texas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		7.2	6.8	6.5
Accretion		0.4	0.3
Change in Cash Flow Estimate		0.0	0.0
Spending		0.0	0.0
System Energy [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		896.0	861.7	854.2
Accretion		34.3	43.4
Change in Cash Flow Estimate		0.0	(35.9)
Spending		0.0	0.0
Entergy Wholesale Commodities [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		0.4	0.3	0.3
Accretion		0.0	0.0
Change in Cash Flow Estimate		0.1	0.0
Spending		0.0	0.0
Entergy Wholesale Commodities [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		3,679.0	3,183.3	3,827.4
Accretion		264.5	272.5
Change in Cash Flow Estimate		410.6	(68.7)
Spending	(727.3)	(179.4)	(120.6)
Big Rock Point [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		39.7	38.9	37.9
Accretion		3.2	3.1
Change in Cash Flow Estimate		0.0	0.0
Spending		(2.4)	(2.1)
FitzPatrick [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation			0.0	714.3
Accretion			13.9
Change in Cash Flow Estimate			0.0
Spending	$ (727.3)		(0.9)
Indian Point 1 [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		227.9	217.6	207.6
Accretion		18.6	17.7
Change in Cash Flow Estimate		0.0	0.0
Spending		(8.3)	(7.7)
Indian Point 2 [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		768.0	708.7	653.1
Accretion		60.6	55.8
Change in Cash Flow Estimate		0.0	0.0
Spending		(1.3)	(0.2)
Indian Point 3 [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		750.6	694.5	641.1
Accretion		58.0	53.5
Change in Cash Flow Estimate		0.0	0.0
Spending		(1.9)	(0.1)
Palisades [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		508.0	470.4	500.3
Accretion		39.6	41.3
Change in Cash Flow Estimate		0.0	(68.7)
Spending		(2.0)	(2.5)
Pilgrim [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		816.5	651.4	602.3
Accretion		58.6	52.8
Change in Cash Flow Estimate		117.5	0.0
Spending		(11.0)	(3.7)
Utility [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		3,244.4	3,002.5	2,879.4
Accretion		159.0	159.0
Change in Cash Flow Estimate		94.8	(35.9)
Spending		(11.9)	0.0
Vermont Yankee [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation		567.9	401.5	$ 470.5
Accretion		25.9	34.4
Change in Cash Flow Estimate		293.0	0.0
Spending		$ (152.5)	$ (103.4)

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.

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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://fasb.org/us-gaap/role/ref/legacyRef
-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://fasb.org/us-gaap/role/ref/legacyRef
-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

+ Details

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Balance Type:	debit
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- Definition

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.

+ References

+ Details

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- Definition

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 35
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(4)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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