Risk Management and Fair Values (Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Entergy Wholesale Commodities [Member]
Derivatives, Fair Value [Line Items]
Cash collateral posted	$ 6.0	$ 5.0
Liabilities:
Letters of Credit Held	7.0	39.0
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	1.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	1.0	1.0
Other Deferred Debits And Other Assets [Member] \| Natural Gas Swaps [Member] \| Utility [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset		1.0
Derivative Asset, Fair Value, Gross Asset		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		38.0
Derivative Asset, Fair Value, Gross Asset		39.0
Derivative, Collateral, Obligation to Return Cash		(1.0)
Prepayments And Other [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	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	4.0	9.0
Derivative Asset, Fair Value, Gross Asset	4.0	9.0
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
Derivative, Collateral, Right to Reclaim Cash		(1.0)
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	2.0	6.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	2.0	6.0
Entergy Louisiana [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.2	0.3
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	0.8
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability	0.8
Entergy Louisiana [Member] \| Other Deferred Debits And Other Assets [Member] \| Natural Gas Swaps [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.4	0.5
Derivative Asset, Fair Value, Gross Asset	0.4	0.5
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	1.0	0.8
Derivative Asset, Fair Value, Gross Asset	1.0	0.8
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	1.2	4.2
Derivative Asset, Fair Value, Gross Asset	1.3	4.3
Derivative, Collateral, Obligation to Return Cash	0.1	(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		0.3
Derivative, Collateral, Right to Reclaim Cash		0.0
Derivative Liability		0.3
Entergy Mississippi [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.4	0.2
Entergy Mississippi [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.3	0.6
Derivative Asset, Fair Value, Gross Asset	0.3	0.6
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	5.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability	2.3	5.0
Entergy New Orleans [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.1	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	0.1
Derivative Asset, Fair Value, Gross Asset	0.1	0.2
Derivative, Collateral, Obligation to Return Cash	0.0	0.1
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		0.3
Derivative, Collateral, Right to Reclaim Cash		0.0
Derivative Liability		0.3
Entergy Arkansas [Member]
Liabilities:
Letters of Credit Outstanding, Amount	0.4
Entergy Arkansas [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	1.4	2.7
Derivative Asset, Fair Value, Gross Asset	1.5	2.9
Derivative, Collateral, Obligation to Return Cash	(0.1)	(0.2)
Entergy Texas [Member]
Liabilities:
Letters of Credit Outstanding, Amount		0.5
Entergy Texas [Member] \| Prepayments And Other [Member] \| Fixed Transmission Rights (FTRs) [Member] \| Not Designated As Hedging Instrument [Member]
Assets:
Derivative Asset	0.5	1.6
Derivative Asset, Fair Value, Gross Asset	0.5	1.6
Derivative, Collateral, Obligation to Return Cash	$ 0.0	$ 0.0

Letters of credit posted to Entergy by its counterparties

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