Common Equity (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		$ 117,059	$ 83,470	$ 11,440
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects	$ 15,500		15,505
Amounts reclassified from accumulated other comprehensive income (loss)		(13,306)	135,275
Other comprehensive income (loss) before reclassifications		130,365	(51,805)
Accumulated other comprehensive loss, Beginning Balance		(446,920)	(557,173)	(23,531)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					$ (6,806)	$ (632,617)
Cash flow hedges net unrealized gain (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		115,026	22,098
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects			(7,756)
Amounts reclassified from accumulated other comprehensive income (loss)		(76,121)	54,031
Other comprehensive income (loss) before reclassifications		191,147	(31,933)
Accumulated other comprehensive loss, Beginning Balance		84,206	(23,135)	(37,477)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					(7,685)	0
Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		(25,150)	90,143
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects			(90,966)
Amounts reclassified from accumulated other comprehensive income (loss)		68,546	63,441
Other comprehensive income (loss) before reclassifications		(93,696)	26,702
Accumulated other comprehensive loss, Beginning Balance		(557,072)	(531,922)	(531,099)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					0	0
Net unrealized investment gains [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		27,183	(28,771)
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects			114,227
Amounts reclassified from accumulated other comprehensive income (loss)		(5,731)	17,803
Other comprehensive income (loss) before reclassifications		32,914	(46,574)
Accumulated other comprehensive loss, Beginning Balance		25,946	(2,116)	545,045
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					879	(632,617)
Entergy Louisiana [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		10,715	50,296	2,042
Accumulated other comprehensive loss, Beginning Balance		4,562	(6,153)
Entergy Louisiana [Member] | Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		10,715	50,296
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects			(10,049)
Amounts reclassified from accumulated other comprehensive income (loss)		(3,876)	(2,003)
Other comprehensive income (loss) before reclassifications		14,591	52,299
Accumulated other comprehensive loss, Beginning Balance		$ 4,562	$ (6,153)	$ (46,400)
Restatement Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(563,979)	(656,148)
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)	(37,477)
Restatement Adjustment [Member] | Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(531,922)	(531,099)
Restatement Adjustment [Member] | Net unrealized investment gains [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					$ (1,237)	$ (87,572)