Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Operating revenues	$ 2,623,845	$ 3,243,628	$ 2,618,550	$ 2,588,458	$ 2,648,528	$ 3,124,703	$ 2,462,562	$ 2,609,852	$ 11,074,481		$ 10,845,645		$ 11,513,251
Operating income (loss)	211,901	729,469	143,509	174,803	(2,599,001)	772,060	442,258	498,218	1,259,682		(886,465)		(299,165)
Consolidated net income (loss)	(475,710)	401,644	413,368	86,051	(1,765,539)	393,204	572,590	235,242	425,353	[1]	(564,503)	[1]	(156,734)	[1]
Net income (loss) attributable to Entergy Corporation	$ (479,113)	$ 398,198	$ 409,922	$ 82,605	$ (1,769,068)	$ 388,170	$ 567,314	$ 229,966	$ 411,612		$ (583,618)		$ (176,562)
Basic earnings per share (in usd per share)	$ (2.67)	$ 2.22	$ 2.28	$ 0.46	$ (9.89)	$ 2.17	$ 3.17	$ 1.29	$ 2.29		$ (3.26)		$ (0.99)
Diluted earnings per share (in usd per share)	$ (2.66)	$ 2.21	$ 2.27	$ 0.46	$ (9.86)	$ 2.16	$ 3.16	$ 1.28	$ 2.28		$ (3.26)		$ (0.99)
Entergy Arkansas [Member]
Operating revenues	$ 495,680	$ 673,226	$ 496,662	$ 474,351	$ 462,384	$ 654,599	$ 504,252	$ 465,373
Operating income (loss)	14,507	169,755	68,994	39,847	29,843	188,660	73,447	54,378	$ 293,103		$ 346,328		$ 179,406
Consolidated net income (loss)	(5,648)	92,638	38,550	14,304	3,879	110,148	33,891	19,294	139,844		167,212		74,272
Net income (loss) attributable to Entergy Corporation	(6,005)	92,281	38,193	13,947	3,521	108,672	32,173	17,576	138,416		161,942		67,399
Entergy Louisiana [Member]
Operating revenues	1,045,839	1,290,494	1,083,434	880,783	973,417	1,249,452	999,034	955,145	4,300,550		4,177,048		4,417,146
Operating income (loss)	210,325	290,089	193,779	152,648	111,066	312,951	193,752	181,618	846,841		799,387		718,332
Consolidated net income (loss)	(88,794)	186,284	124,479	94,378	67,610	189,506	253,325	111,606	316,347		622,047		446,639
Net income (loss) attributable to Entergy Corporation									316,347		622,047		440,902
Entergy Mississippi [Member]
Operating revenues	299,377	349,197	291,212	258,443	273,726	309,739	248,138	263,046
Operating income (loss)	42,169	84,035	55,262	39,608	32,464	88,312	61,890	41,573	221,074		224,239		211,906
Consolidated net income (loss)	18,026	46,545	28,303	17,158	13,260	46,612	32,194	17,118	110,032		109,184		92,708
Net income (loss) attributable to Entergy Corporation	17,788	46,307	28,064	16,920	12,938	45,905	31,487	16,411	109,079		106,741		89,880
Entergy New Orleans [Member]
Operating revenues	171,842	199,017	176,222	168,989	149,867	201,336	164,920	149,340	716,070		665,463		671,446
Operating income (loss)	12,333	33,415	27,606	21,762	8,807	42,279	26,913	21,880	95,116		99,879		84,970
Consolidated net income (loss)	164	18,529	14,882	10,978	2,138	23,701	11,843	11,167	44,553		48,849		44,925
Net income (loss) attributable to Entergy Corporation	46	18,288	14,641	10,737	1,896	23,460	11,602	10,926	43,712		47,884		43,960
Entergy Texas [Member]
Operating revenues	369,569	432,909	378,488	363,927	382,308	442,085	412,922	378,304
Operating income (loss)	33,800	78,950	47,787	38,842	38,338	107,964	58,039	41,269	199,379		245,610		183,645
Consolidated net income (loss)	4,630	39,588	21,101	10,854	12,785	56,133	24,058	14,562	76,173		107,538		69,625
System Energy [Member]
Operating revenues	157,609	156,106	164,956	154,787	145,236	114,039	151,323	137,693
Operating income (loss)	41,073	37,459	40,717	41,544	44,781	43,886	45,020	47,466	160,793		181,153		185,628
Consolidated net income (loss)	$ 18,316	$ 20,583	$ 19,350	$ 20,347	$ 23,326	$ 22,370	$ 25,090	$ 25,958	$ 78,596		$ 96,744		$ 111,318

[1] (a) Consolidated net income and preferred dividend requirements of subsidiaries include $13.7 million for 2017, $19.1 million for 2016, and $14.9 million for 2015 of preferred dividends on subsidiaries’ preferred stock without sinking fund that is not presented as equity.