Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating income (loss)	$ 152,112	$ 778,016	$ 439,311	$ 399,756	$ 248,539	$ 519,929	$ 338,775	$ 283,254	$ 1,769,195	$ 1,390,497	$ 469,365
Consolidated net income	392,547	525,699	365,113	123,294	389,606	369,459	240,533	258,646	1,406,653	1,258,244	862,555
Net Income (Loss) Available to Common Stockholders, Basic	387,968	521,119	360,533	118,714	385,025	365,240	236,424	254,537	1,388,334	1,241,226	848,661
Net Income (Loss) Attributable to Parent									1,388,334	1,241,226	848,661
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,370,101	$ 2,903,568	$ 2,412,788	$ 2,427,179	$ 2,462,305	$ 3,140,575	$ 2,666,209	$ 2,609,584	$ 10,113,636	$ 10,878,673	$ 11,009,452
Basic earnings per share (in usd per share)	$ 1.95	$ 2.60	$ 1.80	$ 0.59	$ 1.96	$ 1.84	$ 1.22	$ 1.34	$ 6.94	$ 6.36	$ 4.68
Diluted earnings per share (in usd per share)	$ 1.93	$ 2.59	$ 1.79	$ 0.59	$ 1.94	$ 1.82	$ 1.22	$ 1.32	$ 6.90	$ 6.30	$ 4.63
Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax									$ 9,046,643	$ 9,429,978	$ 9,384,111
Entergy Arkansas [Member]
Operating income (loss)	$ 9,126	$ 217,648	$ 107,949	$ 67,835	$ 32,576	$ 182,176	$ 69,774	$ 42,471	402,558	326,997	45,229
Consolidated net income	4,624	135,843	60,170	44,595	23,828	149,716	50,299	39,121	245,232	262,964	252,707
Net Income (Loss) Available to Common Stockholders, Basic									245,232	262,964	251,458
Revenue from Contract with Customer, Excluding Assessed Tax									2,084,494	2,259,594
Entergy Arkansas [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	466,426	644,389	491,767	481,912	483,327	687,526	542,929	545,812	2,084,494	2,259,594	2,060,643
Entergy Louisiana [Member]
Operating income (loss)	117,134	324,496	256,412	166,779	164,424	336,754	241,520	153,944	864,821	896,642	675,771
Consolidated net income	499,031	223,466	170,459	189,396	125,560	255,260	183,084	127,633	1,082,352	691,537	675,614
Net Income (Loss) Available to Common Stockholders, Basic									1,082,352	691,537	675,614
Revenue from Contract with Customer, Excluding Assessed Tax	1,007,541	1,120,022	1,011,652	930,647	987,851	1,231,677	1,106,317	959,330	4,069,862	4,285,175	4,296,320
Entergy Louisiana [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax									4,019,063	4,223,027	4,232,541
Entergy Mississippi [Member]
Operating income (loss)	33,466	93,843	67,705	41,181	40,331	87,024	45,607	30,792	236,195	203,754	46,446
Consolidated net income	20,575	58,589	38,893	22,526	21,623	56,237	26,667	15,398	140,583	119,925	126,078
Net Income (Loss) Available to Common Stockholders, Basic									140,583	119,925	125,244
Revenue from Contract with Customer, Excluding Assessed Tax									1,247,854	1,323,043
Entergy Mississippi [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	299,482	356,496	297,954	293,922	339,330	398,732	302,737	282,244	1,247,854	1,323,043	1,335,112
Entergy New Orleans [Member]
Operating income (loss)	12,397	32,322	7,602	12,091	6,164	28,876	17,509	16,136	64,412	68,685	74,192
Consolidated net income	13,773	19,450	4,929	11,186	5,695	24,908	13,003	9,023	49,338	52,629	53,152
Revenue from Contract with Customer, Excluding Assessed Tax	155,132	182,064	147,343	149,302	153,032	194,204	175,793	163,194	633,841	686,223	717,390
Entergy New Orleans [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax									560,632	594,417	624,733
Entergy Texas [Member]
Operating income (loss)	46,040	108,306	56,443	36,060	24,229	69,510	36,022	16,741	246,849	146,502	206,426
Consolidated net income	43,334	92,164	46,868	32,707	25,895	73,224	38,936	21,342	215,073	159,397	162,235
Net Income (Loss) Available to Common Stockholders, Basic	42,863	91,694	46,397	32,237	25,425	73,114	38,936	21,342	213,191	158,817	162,235
Revenue from Contract with Customer, Excluding Assessed Tax									1,587,125	1,488,955
Entergy Texas [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	380,673	494,922	372,194	339,336	342,024	442,877	363,580	340,474	1,587,125	1,488,955	1,605,902
System Energy [Member]
Operating income (loss)	1,303	48,896	31,236	35,309	30,231	29,086	24,300	31,368	116,744	114,985	43,680
Consolidated net income	10,563	31,064	28,991	28,513	26,039	25,031	24,472	23,578	99,131	99,120	94,109
Net Income (Loss) Available to Common Stockholders, Basic									99,131	99,120	94,109
System Energy [Member] | Electricity [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 90,228	$ 148,517	$ 126,049	$ 130,664	$ 148,825	$ 145,472	$ 139,009	$ 140,104	$ 495,458	$ 573,410	$ 456,707