Risk Management and Fair Values (Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Entergy Wholesale Commodities [Member]
Derivatives, Fair Value [Line Items]
Cash collateral posted	$ 1.0	$ 11.0
Liabilities:
Letters of Credit Held	22.0	98.0
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	2.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	1.0	2.0
Other Deferred Debits And Other Assets [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Designated As Hedging Instrument [Member]
Assets:
Derivative Asset		17.0
Derivative Asset, Fair Value, Gross Asset		17.0
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	1.0
Derivative Asset, Fair Value, Gross Asset	1.0	1.0
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	27.0	91.0
Derivative Asset, Fair Value, Gross Asset	29.0	92.0
Derivative, Collateral, Obligation to Return Cash	(2.0)	(1.0)
Prepayments And Other [Member] \| Electricity Swaps And Options [Member] \| Entergy Wholesale Commodities [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.0	10.0
Derivative Asset, Fair Value, Gross Asset	1.0	11.0
Derivative, Collateral, Obligation to Return Cash	0.0	(1.0)
Prepayments And Other [Member] \| Natural Gas Swaps [Member] \| Utility [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	3.0
Derivative Asset, Fair Value, Gross Asset	3.0
Derivative, Collateral, Obligation to Return Cash	0.0
Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Utility and Entergy Wholesale Commodities [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	17.0	10.0
Derivative Asset, Fair Value, Gross Asset	17.0	10.0
Derivative, Collateral, Obligation to Return Cash		0.0
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	1.0	1.0
Derivative, Collateral, Right to Reclaim Cash	(1.0)	(1.0)
Derivative Liability	0.0	0.0
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		2.0
Derivative, Collateral, Right to Reclaim Cash		(2.0)
Derivative Liability		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		5.0
Derivative, Collateral, Right to Reclaim Cash		0.0
Derivative Liability		5.0
Entergy Louisiana [Member]
Liabilities:
Letters of Credit Outstanding, Amount	2.2
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	1.3
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability	1.3
Entergy Louisiana [Member] \| Other Deferred Debits And Other Assets [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.9	0.8
Derivative Asset, Fair Value, Gross Asset	0.9	0.8
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	2.2
Derivative Asset, Fair Value, Gross Asset	2.2
Derivative, Collateral, Obligation to Return Cash	0.0
Entergy Louisiana [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	7.0	4.5
Derivative Asset, Fair Value, Gross Asset	7.1	4.5
Derivative, Collateral, Obligation to Return Cash	0.1	0.0
Entergy Louisiana [Member] \| Other Current Liabilities [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Liabilities:
Derivative Liability, Fair Value, Gross Liability		2.4
Derivative, Collateral, Right to Reclaim Cash		0.0
Derivative Liability		2.4
Entergy Mississippi [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.7	0.2
Entergy Mississippi [Member] \| Prepayments And Other [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.1
Derivative Asset, Fair Value, Gross Asset	1.1
Derivative, Collateral, Obligation to Return Cash	0.0
Entergy Mississippi [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.8	0.8
Derivative Asset, Fair Value, Gross Asset	0.8	0.8
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		2.3
Derivative, Collateral, Right to Reclaim Cash		0.0
Derivative Liability		2.3
Entergy New Orleans [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.2
Entergy New Orleans [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.1	0.3
Derivative Asset, Fair Value, Gross Asset	0.3	0.3
Derivative, Collateral, Obligation to Return Cash	0.2	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		0.2
Derivative, Collateral, Right to Reclaim Cash		0.0
Derivative Liability		0.2
Entergy Arkansas [Member]
Liabilities:
Letters of Credit Outstanding, Amount	1.9
Entergy Arkansas [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	6.3	3.3
Derivative Asset, Fair Value, Gross Asset	6.4	3.4
Derivative, Collateral, Obligation to Return Cash	(0.1)	(0.1)
Entergy Texas [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	2.3	0.9
Derivative Asset, Fair Value, Gross Asset	2.3	1.0
Derivative, Collateral, Obligation to Return Cash	$ 0.0	$ 0.1

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