Risk Management and Fair Values (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 TWh	Dec. 31, 2019 USD ($) GWh MMBTU	Dec. 31, 2018 USD ($) counterparty	Dec. 31, 2017 USD ($)
Risk Management and Fair Values [Abstract]
Included in earnings		$ (9.2)	$ (3.5)	$ 0.9
Cash flow hedges relating to power sales as part of net unrealized gains		108.0
Reclassified from accumulated other comprehensive income (OCI) to operating revenues		91.0
Maturity of cash flow hedges, Tax		20.0	(14.0)	38.0
Change in cash flow hedges due to ineffectiveness			$ (5.9)	$ (3.0)
Power Contracts [Member]
Risk Management and Fair Values [Abstract]
Number of Derivative Contract Counterparties in a Liability Position | counterparty			6
Hedging Liabilities, Noncurrent			$ 34.0
Cash collateral posted		11.0	19.0
Derivative, Collateral, Obligation to Return Cash		1.0
Letters of Credit Held		$ 98.0
Maximum Length of Time Hedged in Cash Flow Hedge		1 year 3 months
Gas Hedge Contracts [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU		40,926,000
Financial Transmission Rights (FTRs) [Member]
Risk Management and Fair Values [Abstract]
Letters of Credit Outstanding, Amount			4.0
Total volume of FTRs outstanding (MWh) | GWh		48,825
Subsequent Event [Member] | Power Contracts [Member]
Risk Management and Fair Values [Abstract]
Planned generation sold forward from non utility nuclear power plants	97.00%
Planned Generation Sold Forward under financial derivatives	65.00%
Total planned generation for remainder of the period | TWh	17.8
Entergy Arkansas [Member] | Financial Transmission Rights (FTRs) [Member]
Risk Management and Fair Values [Abstract]
Total volume of FTRs outstanding (MWh) | GWh		11,078
Entergy Louisiana [Member] | Gas Hedge Contracts [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU		31,040,000
Maximum Length of Time Hedged in Cash Flow Hedge		4 years 3 months
Entergy Louisiana [Member] | Financial Transmission Rights (FTRs) [Member]
Risk Management and Fair Values [Abstract]
Total volume of FTRs outstanding (MWh) | GWh		22,282
Entergy Mississippi [Member] | Gas Hedge Contracts [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU		9,330,000
Maximum Length of Time Hedged in Cash Flow Hedge		10 months
Entergy Mississippi [Member] | Financial Transmission Rights (FTRs) [Member]
Risk Management and Fair Values [Abstract]
Letters of Credit Outstanding, Amount		$ 0.2	0.2
Total volume of FTRs outstanding (MWh) | GWh		6,195
Entergy New Orleans [Member] | Gas Hedge Contracts [Member]
Risk Management and Fair Values [Abstract]
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU		556,000
Maximum Length of Time Hedged in Cash Flow Hedge		3 months
Entergy New Orleans [Member] | Financial Transmission Rights (FTRs) [Member]
Risk Management and Fair Values [Abstract]
Total volume of FTRs outstanding (MWh) | GWh		2,331
Entergy Texas [Member] | Financial Transmission Rights (FTRs) [Member]
Risk Management and Fair Values [Abstract]
Letters of Credit Outstanding, Amount			$ 4.1
Total volume of FTRs outstanding (MWh) | GWh		6,741