Risk Management and Fair Values (Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Utility [Member]
Liabilities:
Letters of Credit Outstanding, Amount		$ 4.0
Entergy Wholesale Commodities [Member]
Derivatives, Fair Value [Line Items]
Cash collateral posted	$ 13.0	19.0
Assets:
Derivative, Collateral, Obligation to Return Cash	(2.0)
Liabilities:
Letters of Credit Held	48.0
Other Non-Current Liabilities [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	2.0	20.0
Derivative, Collateral, Right to Reclaim Cash	(2.0)	(7.0)
Derivative Liability	0.0	13.0
Other Non-Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Utility [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	1.0
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability	1.0
Other Deferred Debits And Other Assets [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	12.0	0.0
Derivative Asset, Fair Value, Gross Asset	14.0	7.0
Derivative, Collateral, Obligation to Return Cash	(2.0)	(7.0)
Other Deferred Debits And Other Assets [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset		1.0
Derivative Asset, Fair Value, Gross Asset		1.0
Derivative, Collateral, Obligation to Return Cash		0.0
Other Deferred Debits And Other Assets [Member] \| Natural Gas Swaps [Member] \| Utility [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.0	2.0
Derivative Asset, Fair Value, Gross Asset	1.0	2.0
Derivative, Collateral, Obligation to Return Cash		0.0
Prepayments And Other [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	30.0	0.0
Derivative Asset, Fair Value, Gross Asset	35.0	32.0
Derivative, Collateral, Obligation to Return Cash	(5.0)	(32.0)
Prepayments And Other [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	6.0	2.0
Derivative Asset, Fair Value, Gross Asset	9.0	4.0
Derivative, Collateral, Obligation to Return Cash	(3.0)	(2.0)
Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Utility and Entergy Wholesale Commodities [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	16.0	15.0
Derivative Asset, Fair Value, Gross Asset	17.0	16.0
Derivative, Collateral, Obligation to Return Cash	(1.0)	(1.0)
Other Current Liabilities [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	5.0	54.0
Derivative, Collateral, Right to Reclaim Cash	(5.0)	(33.0)
Derivative Liability	0.0	21.0
Other Current Liabilities [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	4.0	1.0
Derivative, Collateral, Right to Reclaim Cash	(4.0)	(1.0)
Derivative Liability	0.0	0.0
Other Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Utility [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	4.0	1.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	4.0	1.0
Entergy Louisiana [Member] \| Other Non-Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	1.4
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability	1.4
Entergy Louisiana [Member] \| Other Deferred Debits And Other Assets [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.0	1.6
Derivative Asset, Fair Value, Gross Asset	1.0	1.6
Derivative, Collateral, Obligation to Return Cash	0.0	0.0
Entergy Louisiana [Member] \| Prepayments And Other [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.1	0.3
Derivative Asset, Fair Value, Gross Asset	0.1	0.3
Derivative, Collateral, Obligation to Return Cash	0.0	0.0
Entergy Louisiana [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	9.1	8.3
Derivative Asset, Fair Value, Gross Asset	9.1	8.4
Derivative, Collateral, Obligation to Return Cash	0.0	(0.1)
Entergy Louisiana [Member] \| Other Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	2.2	1.1
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	2.2	1.1
Entergy Mississippi [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.2	0.2
Entergy Mississippi [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.5	2.2
Derivative Asset, Fair Value, Gross Asset	1.5	2.2
Derivative, Collateral, Obligation to Return Cash	0.0	0.0
Entergy Mississippi [Member] \| Other Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	1.1
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability	1.1
Entergy New Orleans [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.7	1.3
Derivative Asset, Fair Value, Gross Asset	0.7	1.3
Derivative, Collateral, Obligation to Return Cash	0.0	0.0
Entergy New Orleans [Member] \| Other Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability	0.1	0.1
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	0.1	0.1
Entergy Arkansas [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	3.9	3.4
Derivative Asset, Fair Value, Gross Asset	4.0	3.6
Derivative, Collateral, Obligation to Return Cash	(0.1)	(0.2)
Entergy Texas [Member]
Liabilities:
Letters of Credit Outstanding, Amount		4.1
Entergy Texas [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.3
Derivative Asset, Fair Value, Gross Asset	1.7
Derivative, Collateral, Obligation to Return Cash	$ (0.4)
Entergy Texas [Member] \| Other Current Liabilities [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability		0.9
Derivative, Collateral, Right to Reclaim Cash		(1.4)
Derivative Liability		$ (0.5)

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