Rate And Regulatory Matters (Narrative) (Details) (USD $)	1 Months Ended				9 Months Ended	12 Months Ended			1 Months Ended							12 Months Ended				12 Months Ended		12 Months Ended			1 Months Ended				12 Months Ended			1 Months Ended															12 Months Ended								12 Months Ended			1 Months Ended						12 Months Ended					1 Months Ended					3 Months Ended						12 Months Ended				1 Months Ended		12 Months Ended						1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Jan. 31, 2013	Aug. 31, 2012	Jun. 30, 2012	Oct. 31, 2009	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jan. 31, 2013 Entergy Louisiana [Member]	Dec. 31, 2012 Entergy Louisiana [Member]	Sep. 30, 2012 Entergy Louisiana [Member]	Aug. 31, 2012 Entergy Louisiana [Member]	May 31, 2012 Entergy Louisiana [Member]	May 31, 2010 Entergy Louisiana [Member]	Nov. 30, 2009 Entergy Louisiana [Member]	Dec. 31, 2012 Entergy Louisiana [Member]	Dec. 31, 2011 Entergy Louisiana [Member]	Dec. 31, 2010 Entergy Louisiana [Member]	Dec. 31, 2008 Entergy Louisiana [Member]	Dec. 31, 2008 Entergy Louisiana [Member] Hurricane Rita [Member]	Jul. 29, 2008 Entergy Louisiana [Member] Hurricane Rita [Member]	Dec. 31, 2010 Entergy Louisiana [Member] Hurricane Gustav and Ike [Member]	Dec. 31, 2009 Entergy Louisiana [Member] Hurricane Gustav and Ike [Member]	Jul. 31, 2010 Entergy Louisiana [Member] Hurricane Gustav and Ike [Member]	Aug. 31, 2012 Entergy Mississippi [Member]	Mar. 31, 2012 Entergy Mississippi [Member]	Jun. 30, 2010 Entergy Mississippi [Member]	Mar. 31, 2010 Entergy Mississippi [Member]	Dec. 31, 2012 Entergy Mississippi [Member]	Dec. 31, 2011 Entergy Mississippi [Member]	Dec. 31, 2010 Entergy Mississippi [Member]	Jan. 31, 2013 Entergy Gulf States Louisiana [Member]	Dec. 31, 2012 Entergy Gulf States Louisiana [Member]	Nov. 30, 2012 Entergy Gulf States Louisiana [Member]	Sep. 30, 2012 Entergy Gulf States Louisiana [Member]	Aug. 31, 2012 Entergy Gulf States Louisiana [Member]	May 31, 2012 Entergy Gulf States Louisiana [Member]	Apr. 30, 2012 Entergy Gulf States Louisiana [Member]	Feb. 29, 2012 Entergy Gulf States Louisiana [Member]	Jan. 31, 2012 Entergy Gulf States Louisiana [Member]	May 31, 2011 Entergy Gulf States Louisiana [Member]	Mar. 31, 2011 Entergy Gulf States Louisiana [Member]	Jan. 31, 2011 Entergy Gulf States Louisiana [Member]	Jun. 30, 2010 Entergy Gulf States Louisiana [Member]	Jan. 31, 2010 Entergy Gulf States Louisiana [Member]	Nov. 30, 2009 Entergy Gulf States Louisiana [Member]	Dec. 31, 2012 Entergy Gulf States Louisiana [Member]	Dec. 31, 2011 Entergy Gulf States Louisiana [Member]	Dec. 31, 2010 Entergy Gulf States Louisiana [Member]	Sep. 30, 2010 Entergy Gulf States Louisiana [Member]	Dec. 31, 2009 Entergy Gulf States Louisiana [Member]	Sep. 30, 2009 Entergy Gulf States Louisiana [Member]	Dec. 31, 2008 Entergy Gulf States Louisiana [Member] Hurricane Rita [Member]	Aug. 26, 2008 Entergy Gulf States Louisiana [Member] Hurricane Rita [Member]	Dec. 31, 2010 Entergy Gulf States Louisiana [Member] Hurricane Gustav and Ike [Member]	Dec. 31, 2009 Entergy Gulf States Louisiana [Member] Hurricane Gustav and Ike [Member]	Jul. 31, 2010 Entergy Gulf States Louisiana [Member] Hurricane Gustav and Ike [Member]	Nov. 30, 2012 Entergy New Orleans [Member]	Aug. 31, 2012 Entergy New Orleans [Member]	May 31, 2012 Entergy New Orleans [Member]	Oct. 31, 2010 Entergy New Orleans [Member]	May 31, 2010 Entergy New Orleans [Member]	Mar. 31, 2007 Entergy New Orleans [Member]	Dec. 31, 2012 Entergy New Orleans [Member]	Dec. 31, 2011 Entergy New Orleans [Member]	Dec. 31, 2010 Entergy New Orleans [Member]	Dec. 31, 2009 Entergy New Orleans [Member]	Dec. 31, 2007 Entergy New Orleans [Member]	Oct. 31, 2012 Entergy Texas [Member]	Sep. 30, 2012 Entergy Texas [Member]	Jul. 31, 2012 Entergy Texas [Member]	Apr. 30, 2012 Entergy Texas [Member]	Nov. 30, 2011 Entergy Texas [Member]	Dec. 31, 2011 Entergy Texas [Member]	Dec. 31, 2010 Entergy Texas [Member]	Sep. 30, 2010 Entergy Texas [Member]	Jun. 30, 2010 Entergy Texas [Member]	May 31, 2010 Entergy Texas [Member]	Dec. 31, 2009 Entergy Texas [Member]	Dec. 31, 2012 Entergy Texas [Member]	Dec. 31, 2011 Entergy Texas [Member]	Dec. 31, 2010 Entergy Texas [Member]	Dec. 31, 2009 Entergy Texas [Member]	Apr. 30, 2007 Entergy Texas [Member] Hurricane Rita [Member]	Aug. 31, 2012 Entergy Arkansas [Member]	Dec. 31, 2012 Entergy Arkansas [Member]	Dec. 31, 2011 Entergy Arkansas [Member]	Dec. 31, 2010 Entergy Arkansas [Member]	Dec. 31, 2012 System Energy [Member]	Dec. 31, 2011 System Energy [Member]	Dec. 31, 2010 System Energy [Member]	Oct. 31, 2009 Minimum [Member]	Dec. 31, 2012 Minimum [Member] Entergy Gulf States Louisiana [Member]	Dec. 31, 2012 Minimum [Member] Entergy Arkansas [Member]	Oct. 31, 2009 Maximum [Member]	Dec. 31, 2012 Maximum [Member] Entergy Gulf States Louisiana [Member]	Dec. 31, 2012 Maximum [Member] Entergy Arkansas [Member]	Dec. 31, 2011 Electric [Member] Entergy New Orleans [Member]	Dec. 31, 2011 Gas [Member] Entergy New Orleans [Member]
Rate and Regulatory Matters [Abstract]
Formula rate plan extension request MISO Only scenario revenue offset																$ 2,000,000
Formula rate plan extension request MISO ITC scenario revenue offset																1,000,000
Formula rate plan extension request sharing mechanism company																40.00%																															40.00%
Formula rate plan extension request sharing mechanism customers																60.00%																															60.00%
Formula rate plan extension request MISO Only scenario common equity basis point range																75.00%																															75.00%
Formula rate plan extension request MISO ITC scenario common equity basis point range																75.00%																															75.00%
Formula rate plan extension request MISO Only scenario midpoint return on common equity																10.40%																															10.40%
Formula rate plan extension request MISO ITC scenario midpoint return on common equity																10.40%																															10.40%
Formula rate plan extension request MISO Only scenario authorized return on common equity																10.40%																															10.40%
Formula rate plan extension request MISO ITC scenario authorized return on common equity																10.40%																															10.40%
Formula rate plan extension request MISO Only scenario revenue increase authorization																145,000,000																															24,000,000
Formula rate plan extension request MISO ITC scenario revenue increase authorization																169,000,000																															28,000,000
Storm Reserve Withdrawal									187,000,000																							65,000,000																										10,000,000
Construction Work In Progress - Hurricane Isaac						250,000,000
Regulatory Asset - Hurricane Isaac						120,000,000
Adjustment To Income Tax Expense						46,300,000
Adjustment To Regulatory Asset For Income Taxes						75,300,000
Adjustment To Accumulated Deferred Income Taxes						29,000,000
Realignment to base rates of SO2 costs																																															18,000,000
Refund to customers including interest	84,000,000		30,600,000																																												2,000,000
Request filed for refund of fuel cost recovery over collections																																																																					78,000,000		37,500,000					77,000,000	66,000,000		71,000,000		43,000,000
Refund for fuel cost recovery														100,000																																																												67,000,000	73,000,000			87,800,000
Earned return on common equity																	11.07%									10.92%					10.65%	11.18%				11.86%	11.94%				11.11%	11.76%			10.50%				10.12%	8.84%		10.87%																			9.80%	9.60%	10.60%
Basis Point Bandwidth																																															10.65%																																																				0.50%
Earnings bandwidth, basis points within bandwidth																																								10.50%							0.75%																																																			0.40%
Rate reduction														100,000																		43,000						100,000
Rate increase																																																																							28,000,000															63,700,000
Entergy Louisiana rate reset increase																																														44,300,000
Cost of Service Rate Change																																				5,700,000	6,500,000									36,900,000
Rate Decrease for Incremental Capacity Costs																																				20,300,000	22,900,000											5,100,000	22,800,000
Rate Increase for Incremental Capacity Costs													18,100,000																																	7,400,000
Electric Base Revenue Increase																																																																	4,900,000
Increase In Base Rate Reflecting Return On Common Equity																																																																									112,000,000
Recommended reduction in return on current rates by LPSC staff																																												800,000
Recommended reduction in return on current rates by LPSC staff																																										200,000
Return on common equity on formula rate plan				10.25%								10.38%	9.63%		10.25%			10.82%																																	10.25%																																									9.45%			11.05%			11.10%	10.75%
Authorized return on common equity																																	9.40%	10.50%				11.54%		10.48%																																								10.125%						10.20%							9.90%			11.40%
Energy settlement refund to customers including interest																																												500,000
Additional rate increase pursuant to a special rate implementation																																													23,900,000
Percentage of LPSC regulated share of River Bend																																																	70.00%																																		70.00%
Increase in the revenue requirement for decommissioning																		3,500,000																															7,800,000
Expected retail jurisdictional cost																																	16,900,000
Increase in Incremental Capacity costs																		2,200,000																															25,200,000
Rate increase value to reflect special formula rate plan rate implementation adjustment																	43,100,000
Rate decrease value to reflect special formula rate plan rate implementation adjustment																	1,100,000
Rate increase value for incremental capacity costs																	9,000
Revenue deficiency																																											300,000
Revenue adjustment cap																												14,500,000
Current rate change limit of two percent of revenues																												2.00%
Proposed rate change limit of four percent of revenues																												4.00%
Deferral as regulatory asset of legal expenses																											3,900,000
Gas Base Revenue Increase																																																																	50,000
Eliminating the 50/50 sharing that had been in the plan																												50.00%
Request for electric base revenue decrease																																																														12,800,000				6,500,000
Request for gas base revenue increase																																																														2,400,000
Electric base rate decrease																																																													18,000,000
Gas rate decrease																																																													0			50,000		1,100,000
Incremental electric rate decrease																																																																		8,500,000
Incremental gas rate decrease																																																																		1,600,000
Deferred plant maintenance expense																																																																		13,400,000
Amount included in electric rates per year to fund the smart energy efficiency programs as per rate case settlement																																																																			3,100,000
Rate Increase requested in Texas rate case																																																																															198,700,000
Earned return on common equity																																																																															11.50%
Revenue requirement to provide supplemental funding																																																																																			2,800,000
Increase in interim rate maximum due to testimony results																																																																																		58,000,000
Interim rate increase subject to refund																																																																																		17,500,000
Electric rate increase																																																																4,900,000
Additional Increase in Texas base rates for bills rendered beginning May 2, 2011																																																																																9,000,000
Amount of disallowed fuel costs for the period April 2007 through June 2009 per settlement with the PUCT																																																																																3,250,000
Increase in Texas base rates for electricity usage beginning August 15, 2010																																																																																		59,000,000
River Bend annual Decommissioning costs per settlement																																																																																2,000,000
Amortization of rate case costs																																																																																11,000,000
Increase in Annual Funding for Storm Reserve																																																												5,700,000
Recommended Increase in Rate Base																																																																								66,000,000
Revised Increase In Rate Base Request																																																																								105,000,000
Amount Collected From Customers																																																																																							156,000,000
Increase in revenues as a result of rate change																																			8,700,000
MISO transition expenses in base rates per PUCT																																																																						1,600,000
Reduction of fuel reconciliation recovery due to disagreement with line loss factor in calculation per PUCT																																																																						4,000,000
Regulatory charge recorded due to probability of non-recovery per PUCT order																																																																						24,000,000
Payments from utility operating companies as percentage of average production cost																																																																																									11.00%
Trapped costs at subsidiary																																																																																18,600,000
Potential cost for Entergy Arkansas for years 2003, 2004, and 2006 based on intra-system bills					12,000,000
Per LPSC, the amount of damages to be paid by Entergy Arkansas to the Utility Operating Companies																7,000,000													23,000,000																		42,000,000																	4,000,000
Per LPSC, amount Entergy Arkansas "Shareholders" should pay customers																																																																																						34,000,000
Financing order authorized to issue storm cost recovery bonds																																																																																				353,000,000				126,300,000
Up front financing costs including in storm cost recovery bonds																																																																																								11,500,000
Carrying costs including in storm cost recovery bonds																																																																																								4,600,000
Total recoverable costs																							394,000,000																																	234,000,000
Unrecoverable storm cost charged to earning																							7,200,000																																	4,400,000
Replenishment amount for storm reserve spending																							200,000,000																																	90,000,000
Minimum amount of benefits committed to pass on to the customers																				30,000,000			27,750,000																														10,000,000			15,500,000
Prospective Annual rate reductions for five years																				6,000,000			5,550,000																														2,000,000			3,100,000
Bond issued by LCDA																					687,700,000	462,400,000		468,900,000																														278,400,000			244,100,000
Amount transfer to restricted escrow account as storm damage reserve by corporation																				152,000,000		200,000,000																															87,000,000		90,000,000
Amount Transferred to Entergy Louisiana																				527,000,000		262,400,000																															187,700,000		150,300,000
Proceed from loan by LCDA to corporation LURC																				679,000,000																																	274,700,000		240,300,000
Provisions for rate refund including interest																			16,000,000
Amount used to acquire membership interest units in wholly owned Subsidiary																				545,000,000		262,400,000																															189,400,000		150,300,000
Class preferred, non-voting, membership interest units																				5,449,861.85		2,624,297.11																															1,893,918.39		1,502,643.04
Annual distribution rate																				10.00%		9.00%																															10.00%		9.00%
Liquidation price per unit																						100																															100		100
Net worth required under terms of membership interest																				1,000,000,000		1,000,000,000																															1,000,000,000		1,000,000,000
Amount withdrawn from restricted escrow account as approved by units of wholly owned subsidiary																				17,800,000																																	1,700,000
Class A preferred membership units sold to third party																																							500,000
Proceeds From Sale of Preferred Membership Units																																							51,000,000
Storm related costs																																																															205,000,000
Amount received for CDBG funds																																																																		19,200,000		180,800,000
Amount authorized for storm reserve																																																																				75,000,000
Operation and maintenance expense						3,045,392,000	2,867,758,000	2,969,402,000								449,172,000	470,783,000	432,341,000											244,722,000	210,657,000	217,354,000																361,415,000	351,070,000	361,329,000															122,143,000	106,817,000	130,917,000														233,503,000	214,191,000	209,699,000				545,782,000	511,592,000	495,443,000	149,346,000	136,495,000	124,690,000
Cost incurred in planning evaluation and monitoring																														57,000,000
Charges Above Prevailing Market Prices						57,000,000
Low Damages Range In Texas Lawsuit						153,000,000
High Damages Range in Texas Lawsuit						972,000,000
Income before income taxes						899,218,000	1,653,635,000	1,887,544,000								152,159,000	103,712,000	297,981,000											105,447,000	137,530,000	135,488,000																211,593,000	291,340,000	266,616,000															24,305,000	51,838,000	47,715,000														75,089,000	130,337,000	108,583,000				247,171,000	297,656,000	285,562,000	188,981,000	139,150,000	138,673,000
Estimated Hurricane Isaac Total Restoration Costs		370,000,000										220,000,000													22,000,000											70,000,000																							48,000,000																										7,000,000
Estimated Arkansas 2012 Winter Storm Total Restoration Costs																																																																																														55,000,000			65,000,000
Entergy Arkansas 2012 Winter Storm Related Regulatory Asset																																																																																						21,000,000
Entergy Arkansas 2012 Winter Storm Related CWIP																																																																																						37,000,000
Refund to customers per LPSC Staff January 2013 audit report									1,900,000
Realignment of the recovery from Entergy Louisiana's fuel adjustment clause to base rates per LPSC January 2013 audit report									1,000,000
Rate increase effective for the November 2009 billing cycle															2,500,000
Cost of service adjustment effective for the November 2009 billing cycle															16,300,000
Net reduction for decreased capacity costs and a base rate reclassification for the November 2009 billing cycle															13,800,000
Change in recovery of capacity costs from fuel adjustment clause recovery to base rate recovery														12,500,000
Increase in incremental capacity rider												15,900,000
Rate change contribution to Entergy Louisiana's 2012 revenues											5,300,000
Reduction for first-year capacity charges for purchase by Entergy Gulf States Louisiana from Entergy Louisiana of one-third of Acadia Unit 2 capacity and energy										17,000,000
Increase for first year retail revenue requirement associated with W3 replacement steam generator project										$ 88,000,000