Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating income (loss)	$ 248,539	$ 519,929	$ 338,775	$ 283,254	$ (228,931)	$ 271,035	$ 91,597	$ 335,664	$ 1,390,497	$ 469,365	$ 1,360,407
Consolidated net income	389,606	369,459	240,533	258,646	(62,323)	539,818	248,860	136,200	1,258,244	862,555	425,353
Net Income (Loss) Available to Common Stockholders, Basic	385,025	365,240	236,424	254,537	(65,900)	536,379	245,421	132,761	1,241,226	848,661	411,612
Net Income (Loss) Attributable to Parent									1,241,226	848,661	411,612
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,462,305	$ 3,140,575	$ 2,666,209	$ 2,609,584	$ 2,512,482	$ 3,104,319	$ 2,668,770	$ 2,723,881	$ 10,878,673	$ 11,009,452	$ 11,074,481
Basic earnings per share (in usd per share)	$ 1.96	$ 1.84	$ 1.22	$ 1.34	$ (0.37)	$ 2.96	$ 1.36	$ 0.73	$ 6.36	$ 4.68	$ 2.29
Diluted earnings per share (in usd per share)	$ 1.94	$ 1.82	$ 1.22	$ 1.32	$ (0.36)	$ 2.92	$ 1.34	$ 0.73	$ 6.30	$ 4.63	$ 2.28
Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax									$ 9,429,978	$ 9,384,111	$ 9,278,895
Entergy Arkansas [Member]
Operating income (loss)	$ 32,576	$ 182,176	$ 69,774	$ 42,471	$ (82,704)	$ 34,785	$ 26,501	$ 66,647	326,997	45,229	306,771
Consolidated net income	23,828	149,716	50,299	39,121	5,006	128,890	82,556	36,255	262,964	252,707	139,844
Net Income (Loss) Available to Common Stockholders, Basic	23,828	149,716	50,299	39,121	4,828	128,533	82,199	35,898	262,964	251,458	138,416
Revenue from Contract with Customer, Excluding Assessed Tax									2,259,594	2,060,643
Entergy Arkansas [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	483,327	687,526	542,929	545,812	446,615	568,399	494,605	551,024	2,259,594	2,060,643	2,139,919
Entergy Louisiana [Member]
Operating income (loss)	164,424	336,754	241,520	153,944	147,774	236,518	150,160	141,319	896,642	675,771	874,637
Consolidated net income	125,560	255,260	183,084	127,633	161,355	218,308	184,358	111,593	691,537	675,614	316,347
Net Income (Loss) Available to Common Stockholders, Basic									691,537	675,614	316,347
Revenue from Contract with Customer, Excluding Assessed Tax	987,851	1,231,677	1,106,317	959,330	987,576	1,206,612	1,072,788	1,029,344	4,285,175	4,296,320	4,300,550
Entergy Louisiana [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax									4,223,027	4,232,541	4,246,020
Entergy Mississippi [Member]
Operating income (loss)	40,331	87,024	45,607	30,792	23,600	45,215	(63,801)	41,432	203,754	46,446	223,816
Consolidated net income	21,623	56,237	26,667	15,398	14,260	50,733	38,242	22,843	119,925	126,078	110,032
Net Income (Loss) Available to Common Stockholders, Basic	21,623	56,237	26,667	15,398	14,141	50,495	38,003	22,605	119,925	125,244	109,079
Revenue from Contract with Customer, Excluding Assessed Tax									1,323,043	1,335,112
Entergy Mississippi [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	339,330	398,732	302,737	282,244	297,946	367,734	353,689	315,743	1,323,043	1,335,112	1,198,229
Entergy New Orleans [Member]
Operating income (loss)	6,164	28,876	17,509	16,136	6,836	21,544	27,943	17,869	68,685	74,192	96,409
Consolidated net income	5,695	24,908	13,003	9,023	2,594	21,407	18,269	10,882	52,629	53,152	44,553
Net Income (Loss) Available to Common Stockholders, Basic	5,695	24,908	13,003	9,023	2,594	21,407	18,269	10,882	52,629	53,152	43,712
Revenue from Contract with Customer, Excluding Assessed Tax	153,032	194,204	175,793	163,194	150,487	200,182	178,446	188,275	686,223	717,390	716,070
Entergy New Orleans [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax									594,417	624,733	631,744
Entergy Texas [Member]
Operating income (loss)	24,229	69,510	36,022	16,741	6,741	99,966	58,637	41,082	146,502	206,426	199,558
Consolidated net income	25,895	73,224	38,936	21,342	48,250	65,846	30,789	17,350	159,397	162,235	76,173
Net Income (Loss) Available to Common Stockholders, Basic	25,425	73,114	38,936	21,342	48,250	65,846	30,789	17,350	158,817	162,235	76,173
Revenue from Contract with Customer, Excluding Assessed Tax									1,488,955	1,605,902
Entergy Texas [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	342,024	442,877	363,580	340,474	376,245	477,231	403,486	348,940	1,488,955	1,605,902	1,544,893
System Energy [Member]
Operating income (loss)	30,231	29,086	24,300	31,368	7,212	(17,879)	23,406	30,941	114,985	43,680	166,983
Consolidated net income	26,039	25,031	24,472	23,578	25,442	22,972	23,387	22,308	99,120	94,109	78,596
Net Income (Loss) Available to Common Stockholders, Basic									99,120	94,109	78,596
System Energy [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 148,825	$ 145,472	$ 139,009	$ 140,104	$ 116,843	$ 78,965	$ 112,456	$ 148,443	$ 573,410	$ 456,707	$ 633,458