Common Equity Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		$ (2,287)	$ 117,059	$ 83,470
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects	$ 15,500
Amounts reclassified from accumulated other comprehensive income (loss)		(55,456)	(13,306)
Other comprehensive income (loss) before reclassifications		53,169	130,365
Accumulated other comprehensive loss, Beginning Balance		(449,207)	(446,920)	(557,173)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					$ (6,806)	$ (633,000)
Cash flow hedges net unrealized gain (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		(55,487)	115,026
Amounts reclassified from accumulated other comprehensive income (loss)		(116,415)	(76,121)
Other comprehensive income (loss) before reclassifications		60,928	191,147
Accumulated other comprehensive loss, Beginning Balance		28,719	84,206	(23,135)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					(7,685)
Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		22,496	(25,150)
Amounts reclassified from accumulated other comprehensive income (loss)		71,609	68,546
Other comprehensive income (loss) before reclassifications		(49,113)	(93,696)
Accumulated other comprehensive loss, Beginning Balance		(534,576)	(557,072)	(531,922)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					0
Net unrealized investment gains [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		30,704	27,183
Amounts reclassified from accumulated other comprehensive income (loss)		(10,650)	(5,731)
Other comprehensive income (loss) before reclassifications		41,354	32,914
Accumulated other comprehensive loss, Beginning Balance		56,650	25,946	(2,116)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					879
Entergy Louisiana [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		(235)	10,715	50,296
Accumulated other comprehensive loss, Beginning Balance		4,327	4,562
Entergy Louisiana [Member] | Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		(235)	10,715
Amounts reclassified from accumulated other comprehensive income (loss)		(3,237)	(3,876)
Other comprehensive income (loss) before reclassifications		3,002	14,591
Accumulated other comprehensive loss, Beginning Balance		$ 4,327	$ 4,562	$ (6,153)
Restatement Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(563,979)
Restatement Adjustment [Member] | Cash flow hedges net unrealized gain (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(30,820)
Restatement Adjustment [Member] | Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(531,922)
Restatement Adjustment [Member] | Net unrealized investment gains [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					$ (1,237)