Risk Management and Fair Values (Narrative) (Details) TWh in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) MMBTU GWh	Jun. 30, 2019 USD ($)	Dec. 31, 2020 TWh	Jun. 30, 2020 USD ($) MMBTU GWh	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Cash flow hedges relating to power sales as part of net unrealized gains				$ 48.0
Reclassified from accumulated other comprehensive income (OCI) to operating revenues				48.0
Maturity of cash flow hedges, Tax	$ 5.0	$ 1.0		$ 25.0	$ 12.0
Maximum length of time over which Company is currently hedging the variability in future cash flows for forecasted power transactions, years				9 months
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU	37,862,000			37,862,000
Total volume of fixed transmission rights outstanding | GWh	129,379			129,379
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset and Liability Unrealized Gains (Loss) Included in Earnings	$ 3.0	$ 1.4		$ 4.0	$ (3.5)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0.4			0.4
Letters Of Credit	6.0			6.0
Entergy Arkansas [Member]
Letters of Credit Outstanding, Amount	$ 3.1			$ 3.1
Total volume of fixed transmission rights outstanding | GWh	30,375			30,375
Entergy Louisiana [Member]
Letters of Credit Outstanding, Amount	$ 2.3			$ 2.3
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU	27,400,000			27,400,000
Total volume of fixed transmission rights outstanding | GWh	61,443			61,443
Entergy Mississippi [Member]
Letters of Credit Outstanding, Amount	$ 1.5			$ 1.5		$ 0.2
Total volume of natural gas swaps outstanding (MMBtu) | MMBTU	10,462,000			10,462,000
Total volume of fixed transmission rights outstanding | GWh	14,461			14,461
Entergy New Orleans [Member]
Letters of Credit Outstanding, Amount	$ 0.5			$ 0.5
Total volume of fixed transmission rights outstanding | GWh	5,873			5,873
Entergy Texas [Member]
Letters of Credit Outstanding, Amount	$ 0.4			$ 0.4
Total volume of fixed transmission rights outstanding | GWh	16,793			16,793
Entergy Wholesale Commodities [Member]
Derivative, Collateral, Obligation to Return Cash						1.0
Letters of Credit Held						98.0
Gas Hedge Contracts [Member] | Entergy Louisiana [Member]
Maximum Length of Time Hedged in Cash Flow Hedge				3 years 9 months
Gas Hedge Contracts [Member] | Entergy Mississippi [Member]
Maximum Length of Time Hedged in Cash Flow Hedge				9 months
Entergy Wholesale Commodities [Member]
Cash collateral posted	$ 6.0			$ 6.0		11.0
Letters of Credit Held	41.0			41.0
Collateral Held						1.0
Letters Of Credit	$ 8.0			$ 8.0
Utility [Member]
Letters of Credit Outstanding, Amount						$ 98.0
Subsequent Event [Member]
Planned generation sold forward from non utility nuclear power plants for the remainder of the period			97.00%
Planned Generation From Non Nuclear Power Plants Sold Forward Under Financial Hedges			61.00%
Total planned generation for remainder of the period | TWh			7.2