Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended				3 Months Ended			12 Months Ended
	Aug. 31, 2015	Sep. 30, 2013	Aug. 31, 2008	Jul. 31, 2008	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2009	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 31, 2015
Income Taxes [Line Items]
Valuation allowance on the deferred tax assets related to state net operating loss carryovers					$ 46,000			$ 46,000	$ 21,000
Unrecognized tax benefits if recognized, would lower the effective income tax rates					955,000			955,000	516,000	$ 176,000
Remaining balances of unrecognized tax benefits, effective income tax rates					1,657,000			1,657,000	4,221,000	4,417,000
Accrued income tax interest and penalties					27,000			27,000	127,000	96,400
Regulatory Liabilities												$ 107,000
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		$ (585,000)
Deferred Income Taxes and Tax Credits								(820,350)	596,935	311,789
Deferred Tax Assets, Valuation Allowance					91,532			91,532	27,387
Income tax benefit resulting from 2006-2007 audit						$ 20,000
Tax Deduction Related to Nuclear Decommissioning Tax Liability	$ 118,000
2009 tax claim related to nuclear decommissioning liability	9,300,000
Increase to 2009 Federal Income Tax Liability	$ 2,400
Other					68,204			68,204	58,334			334,000
Regulatory Liability, Noncurrent					1,414,898			1,414,898	1,383,609			107,000
Regulatory Liability Net Of Tax												$ 66,000
Valuation allowances on deferred tax assets related to state jurisdictions					45,500			45,500
Parent Company [Member]
Income Taxes [Line Items]
Reduction in taxable income relating to 2009 CAM settlement							$ 5,700,000
Adjustment 2009 CAM											$ 9,300,000
Entergy Arkansas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					4,500			4,500	2,600	600
Accrued income tax interest and penalties					1,300			1,300	17,000	15,200
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		(177,000)
Deferred Income Taxes and Tax Credits								(4,330)	130,132	130,707
Income tax benefit resulting from 2006-2007 audit						4,000
Other					128			128	258
Regulatory Liability, Noncurrent					242,913			242,913	254,036
Entergy Louisiana [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					692,700			692,700	267,300	131,900
Accrued income tax interest and penalties					9,300			9,300	22,200	18,000
Regulatory Liabilities					68,300			68,300	82,600
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		(78,000)
Deferred Income Taxes and Tax Credits								97,461	248,686	397,089
Income tax benefit resulting from 2006-2007 audit						11,000
Other					21,982			21,982	15,508
Regulatory Liability, Noncurrent					818,623			818,623	722,389
Noncash Capital Contribution from Parent								267,826	0	0
Change in accounting method for tax purposes, effect of change on taxable income					2,200,000
Entergy Mississippi [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					8,100			8,100	3,900	3,900
Accrued income tax interest and penalties					400			400	2,800	2,100
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		(26,000)
Deferred Income Taxes and Tax Credits								18,673	32,472	47,878
Other					1,995			1,995	5,887
Entergy New Orleans [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					50,700			50,700	50,700	0
Accrued income tax interest and penalties					1,800			1,800	1,300	900
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		2,000
Deferred Income Taxes and Tax Credits								22,180	24,380	(7,439)
Other					316			316	2,891
Entergy Texas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					5,200			5,200	10,500	10,100
Accrued income tax interest and penalties					1,200			1,200	1,000	800
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		(183,000)
Deferred Income Taxes and Tax Credits								(23,292)	2,829	86,152
Other					1,672			1,672	3,850
Regulatory Liability, Noncurrent					6,396			6,396	5,125
System Energy [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					700			700	3,700	3,300
Accrued income tax interest and penalties					700			700	23,800	19,000
(Reduction) Increase in repairs and maintenance tax deduction as a result of IRS regulations		$ 22,000
Deferred Income Taxes and Tax Credits								200,797	79,835	$ 29,996
Income tax benefit resulting from 2006-2007 audit						$ 1,000
Other					0			0	2,000
Regulatory Liability, Noncurrent					337,424			$ 337,424	$ 371,110
Change in accounting method for tax purposes, effect of change on taxable income					$ 1,200,000
Hurricane Rita [Member] | Entergy Gulf States Louisiana [Member]
Income Taxes [Line Items]
Proceeds from LURC			$ 274,700
Proceed from loan by LCDA to corporation LURC			$ 274,700
Hurricane Rita [Member] | Entergy Louisiana [Member]
Income Taxes [Line Items]
Proceeds from LURC				$ 679,000
Proceed from loan by LCDA to corporation LURC				$ 679,000