Risk Management and Fair Values (Narrative) (Details) TWh in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2021 USD ($) GWh MMBTU counterparty	Mar. 31, 2020 USD ($)	Dec. 31, 2021 TWh	Dec. 31, 2020 USD ($)
Maturity of cash flow hedges, Tax	$ 8.0	$ 20.0
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU	41,296,000
Total volume of fixed transmission rights outstanding | GWh	23,009
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset and Liability Unrealized Gains (Loss) Included in Earnings	$ 0.7	1.0
Debt Securities, Available-for-sale, Allowance for Credit Loss	6.4			$ 0.1
Letters Of Credit	$ 6.0
Number of Derivative Contract Counterparties in a Liability Position | counterparty	1
Entergy Arkansas [Member]
Letters of Credit Outstanding, Amount	$ 0.4
Total volume of fixed transmission rights outstanding | GWh	5,765
Entergy Louisiana [Member]
Letters of Credit Outstanding, Amount	$ 0.2			0.3
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU	21,920,000
Total volume of fixed transmission rights outstanding | GWh	10,716
Entergy Mississippi [Member]
Letters of Credit Outstanding, Amount	$ 0.4			0.2
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU	19,376,000
Total volume of fixed transmission rights outstanding | GWh	2,576
Entergy New Orleans [Member]
Letters of Credit Outstanding, Amount	$ 0.1			0.2
Total volume of fixed transmission rights outstanding | GWh	1,055
Entergy Texas [Member]
Letters of Credit Outstanding, Amount				0.5
Total volume of fixed transmission rights outstanding | GWh	2,820
Entergy Wholesale Commodities [Member]
Letters of Credit Held				39.0
Gas Hedge Contracts [Member] | Entergy Louisiana [Member]
Maximum Length of Time Hedged in Cash Flow Hedge	3 years
Gas Hedge Contracts [Member] | Entergy Mississippi [Member]
Maximum Length of Time Hedged in Cash Flow Hedge	7 months
Electricity Swaps And Options [Member] | Cash Flow Hedging [Member] | Competitive Businesses Operating Revenues [Member]
Maturity of cash flow hedges, before taxes	$ 39.0	$ 94.0
Power Sales [Domain] | Cash Flow Hedging [Member] | Competitive Businesses Operating Revenues [Member]
Maturity of cash flow hedges, before taxes	0.3
Entergy Wholesale Commodities [Member]
Cash collateral posted	6.0			5.0
Letters of Credit Held	7.0			39.0
Letters Of Credit	1.0			$ 1.0
Hedging Liabilities, Current	$ 1.0
Subsequent Event [Member]
Planned generation sold forward from non utility nuclear power plants for the remainder of the period			98.00%
Planned Generation From Non Nuclear Power Plants Sold Forward Under Financial Hedges			12.00%
Total planned generation for remainder of the period | TWh			5.8