Common Equity (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		$ 83,470	$ 11,440	$ (43,922)
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)		135,275	(83,484)
Other comprehensive income (loss) before reclassifications		(51,805)	94,924
Accumulated other comprehensive loss, Beginning Balance		(557,173)	(23,531)	(34,971)
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					$ (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		22,098	(41,470)
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects		(7,756)
Amounts reclassified from accumulated other comprehensive income (loss)		54,031	(70,072)
Other comprehensive income (loss) before reclassifications		(31,933)	28,602
Accumulated other comprehensive loss, Beginning Balance		(23,135)	(37,477)	3,993
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					0
Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		90,143	(61,653)
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects		(90,966)
Amounts reclassified from accumulated other comprehensive income (loss)		63,441	42,376
Other comprehensive income (loss) before reclassifications		26,702	(104,029)
Accumulated other comprehensive loss, Beginning Balance		(531,922)	(531,099)	(469,446)
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		(28,771)	115,311
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects		114,227
Amounts reclassified from accumulated other comprehensive income (loss)		17,803	(55,788)
Other comprehensive income (loss) before reclassifications		(46,574)	171,099
Accumulated other comprehensive loss, Beginning Balance		(2,116)	545,045	429,734
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax					(632,617)
Foreign currency translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period			(748)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income (loss) before reclassifications			(748)
Accumulated other comprehensive loss, Beginning Balance			0	748
Entergy Louisiana [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		50,296	2,042	7,970
Accumulated other comprehensive loss, Beginning Balance		(6,153)	(46,400)
Entergy Louisiana [Member] | Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss) for the period		50,296	2,042
Tax Cuts and Jobs Act, Reclassification from AOCI resulting from stranded tax effects		(10,049)
Amounts reclassified from accumulated other comprehensive income (loss)		(2,003)	(1,420)
Other comprehensive income (loss) before reclassifications		52,299	3,462
Accumulated other comprehensive loss, Beginning Balance		$ (6,153)	$ (46,400)	$ (48,442)
Restatement Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(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					(37,477)
Restatement Adjustment [Member] | Pension and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					(531,099)
Restatement Adjustment [Member] | Net unrealized investment gains [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, Beginning Balance					$ (87,572)