Income Taxes (Significant Components Of Accumulated Deferred Income Taxes And Taxes Accrued) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Plant basis differences - net	$ (8,240,342)	$ (7,043,758)
Regulatory assets for income taxes - net	(898,143)	(930,370)
Nuclear decommissioning trusts	(848,918)	(553,558)
Combined unitary state taxes	(233,210)	(227,427)
Power purchase agreements		(17,138)
Other	(485,550)	(402,097)
Total	(10,706,163)	(9,174,348)
Accumulated deferred investment tax credit	110,690	108,338
Nuclear decommissioning liabilities	733,103	612,945
Regulatory liabilities	404,852	197,554
Pension and other post-employment benefits	358,893	315,134
Sale and leaseback	195,074	217,430
Provision for contingencies	61,576	28,504
Power purchase agreements	43,717
Net operating loss carryforwards	960,235	253,518
Capital losses	13,631	12,995
Other	141,592	160,620
Valuation allowance	(86,881)	(85,615)
Total	2,936,482	1,821,423
Noncurrent accrued taxes (including unrecognized tax benefits)	(210,534)	(814,597)
Accumulated deferred income taxes and taxes accrued	(7,980,215)	(8,167,522)
Entergy Arkansas [Member]
Plant basis differences - net	(1,565,988)	(1,334,016)
Regulatory assets for income taxes - net	(172,915)	(222,429)
Nuclear decommissioning trusts	(67,025)	(53,789)
Deferred fuel	(50,068)	(82,452)
Other	(55,000)	(54,277)
Total	(1,910,996)	(1,746,963)
Accumulated deferred investment tax credit	16,062	16,843
Nuclear decommissioning liabilities	(63,189)	(104,862)
Regulatory liabilities	79,805	29,473
Pension and other post-employment benefits	(75,278)	(75,399)
Provision for contingencies	4,723	4,167
Power purchase agreements	94	94
Unbilled/deferred revenues	27,651	15,222
Compensation	3,587
Net operating loss carryforwards	102,034
Other	5,565	56,116
Total	101,054	(58,346)
Noncurrent accrued taxes (including unrecognized tax benefits)	46,930	(27,718)
Accumulated deferred income taxes and taxes accrued	(1,763,012)	(1,833,027)
Entergy Gulf States Louisiana [Member]
Plant basis differences - net	(1,268,164)	(1,124,284)
Regulatory assets for income taxes - net	(100,578)	(103,585)
Nuclear decommissioning trusts	(25,472)	(21,096)
Deferred fuel	(1,618)	(1,225)
Other	(27,501)	(1,394)
Total	(1,423,333)	(1,251,584)
Accumulated deferred investment tax credit	36,642	31,367
Nuclear decommissioning liabilities	51,593	(38,683)
Regulatory liabilities	47,474	(39,265)
Pension and other post-employment benefits	47,469	123,085
Provision for contingencies	33,074	(1,406)
Power purchase agreements	37,771	3,938
Unbilled/deferred revenues	(23,150)	(21,918)
Compensation	580
Other	6,106	27,548
Total	237,559	84,666
Noncurrent accrued taxes (including unrecognized tax benefits)	(239,670)	(206,752)
Accumulated deferred income taxes and taxes accrued	(1,425,444)	(1,373,670)
Entergy Louisiana [Member]
Plant basis differences - net	(1,544,256)	(1,077,835)
Regulatory assets for income taxes - net	(249,051)	(249,459)
Nuclear decommissioning trusts	(29,493)	(22,441)
Deferred fuel	(11,815)	(4,285)
Other	(92,433)	(26,237)
Total	(1,927,048)	(1,380,257)
Accumulated deferred investment tax credit	27,008	28,197
Nuclear decommissioning liabilities	92,930	56,399
Regulatory liabilities	173,046	111,705
Pension and other post-employment benefits	34,283	19,866
Sale and leaseback	57,423	66,801
Provision for contingencies	48,241	3,940
Power purchase agreements		(1)
Unbilled/deferred revenues	(7,101)	(7,108)
Compensation	18
Net operating loss carryforwards	460,367	39,153
Other	5,513	33,675
Total	891,728	352,627
Noncurrent accrued taxes (including unrecognized tax benefits)	218,033	(75,750)
Accumulated deferred income taxes and taxes accrued	(817,287)	(1,103,380)
Entergy Mississippi [Member]
Plant basis differences - net	(727,442)	(608,596)
Regulatory assets for income taxes - net	(27,077)	(32,611)
Deferred fuel	(11,332)	718
Other	(12,641)	(7,263)
Total	(778,492)	(647,752)
Accumulated deferred investment tax credit	2,776	2,437
Regulatory liabilities	8,515	1,497
Pension and other post-employment benefits	(22,140)	(30,390)
Provision for contingencies	9,564	2,465
Power purchase agreements	84	2,383
Unbilled/deferred revenues	9,242	8,990
Compensation	(664)
Net operating loss carryforwards	45,475
Other	8,758	6,206
Total	61,610	(6,412)
Noncurrent accrued taxes (including unrecognized tax benefits)	(1,121)	(6,271)
Accumulated deferred income taxes and taxes accrued	(718,003)	(660,435)
Entergy New Orleans [Member]
Plant basis differences - net	(202,496)	(148,296)
Regulatory assets for income taxes - net	(4,790)
Deferred fuel	(976)	(331)
Other	(10,576)	(18,319)
Total	(218,838)	(166,946)
Accumulated deferred investment tax credit	500	592
Regulatory liabilities	47,257	53,191
Pension and other post-employment benefits	(10,815)	(11,713)
Provision for contingencies	(2,865)	10,121
Power purchase agreements	21	22
Unbilled/deferred revenues	3,352	2,707
Compensation	13
Other	4,472	1,899
Total	41,935	56,819
Noncurrent accrued taxes (including unrecognized tax benefits)	13,630	(27,859)
Accumulated deferred income taxes and taxes accrued	(163,273)	(137,986)
Entergy Texas [Member]
Plant basis differences - net	(770,084)	(735,310)
Regulatory assets for income taxes - net	(220,417)	(227,224)
Deferred fuel	3,932	3,932
Other	(23,681)	(14,098)
Total	(1,010,250)	(972,700)
Accumulated deferred investment tax credit	6,210	6,769
Regulatory liabilities	3,429	35,072
Pension and other post-employment benefits	(40,389)	(41,964)
Provision for contingencies	(35,505)	2,299
Power purchase agreements	2,752	2,547
Unbilled/deferred revenues	12,986	14,324
Compensation	4,547
Net operating loss carryforwards	20,307	58,547
Other	6,707	8,753
Total	(18,956)	86,347
Noncurrent accrued taxes (including unrecognized tax benefits)	55,113	39,799
Accumulated deferred income taxes and taxes accrued	(974,093)	(846,554)
System Energy [Member]
Plant basis differences - net	(759,896)	(505,369)
Regulatory assets for income taxes - net	(119,209)	(120,886)
Nuclear decommissioning trusts	(27,809)	(19,138)
Deferred fuel	(445)	(8)
Other	(6,592)	(9,333)
Total	(913,951)	(654,734)
Accumulated deferred investment tax credit	21,492	22,133
Nuclear decommissioning liabilities	(65,564)	(47,360)
Regulatory liabilities	45,327	18,301
Pension and other post-employment benefits	(19,160)	(19,593)
Sale and leaseback	137,651	150,629
Compensation	180
Net operating loss carryforwards	86,228
Other	2,000	40,759
Total	208,154	164,869
Noncurrent accrued taxes (including unrecognized tax benefits)	(4,130)	(165,981)
Accumulated deferred income taxes and taxes accrued	$ (709,927)	$ (655,846)