Income Taxes (Narrative) (Details) - USD ($)		1 Months Ended			3 Months Ended		12 Months Ended
	Jan. 01, 2018	Aug. 31, 2015	Aug. 31, 2008	Jul. 31, 2008	Mar. 31, 2015	Dec. 31, 2009	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2012	Dec. 31, 2010	Mar. 31, 2017	Jun. 30, 2016	Oct. 31, 2015
Income Taxes [Line Items]
Reduction in taxable income relating to 2009 CAM settlement						$ 5,700,000,000
Valuation allowance on the deferred tax assets related to state net operating loss carryovers							$ 106,000,000	$ 62,000,000
Unrecognized tax benefits if recognized, would lower the effective income tax rates							1,462,000,000	1,240,000,000	$ 955,000,000				$ 63,500,000
Remaining balances of unrecognized tax benefits, effective income tax rates							3,410,000,000	2,670,000,000	1,657,000,000
Accrued income tax interest and penalties							38,000,000	30,000,000	27,000,000
Adjustment 2009 CAM										$ 9,300,000,000
Deferred Income Taxes and Tax Credits							529,053,000	(836,257,000)	(820,350,000)
Deferred Tax Assets, Valuation Allowance							137,283,000	104,277,000
Income tax benefit resulting from 2006-2007 audit					$ 20,000,000
Tax Deduction Related to Nuclear Decommissioning Tax Liability		$ 118,000,000
Increase to 2009 Federal Income Tax Liability		$ 2,400,000
Other							0	0	333,655,000
Regulatory Liability, Noncurrent							$ 1,588,520,000	1,572,929,000						$ 107,000,000
Regulatory Liability Net Of Tax														$ 66,000,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%						35.00%
Increase (Reduction) in income tax resulting from Entergy Wholesale Commodities restructuring							$ 373,277,000	237,760,000	0
Valuation allowances on deferred tax assets related to state jurisdictions							31,000,000	42,300,000
Effective Income Tax Rate Reconciliation, Fitzpatrick Disposition, Amount							44,344,000	0	0
Annual Limit on Deduction for Compensation of Certain Covered Employees	$ 1,000,000
Regulatory Liability For Income Taxes Net							2,900,204,000	0
Limit on Annual Net Operating Loss as a Percent of Annual Taxable Income	80.00%
Net Decrease in Deferred Tax Assets Related to Excess ADIT							560,000,000
Write-off of deferred tax asset resulting from implementation of accounting standard												$ 11,500,000
Entergy Arkansas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates							2,600,000	3,600,000	4,500,000
Accrued income tax interest and penalties							1,600,000	1,400,000	1,300,000
Deferred Income Taxes and Tax Credits							67,711,000	201,219,000	(4,330,000)
Income tax benefit resulting from 2006-2007 audit					4,000,000
Regulatory Liability, Noncurrent							363,591,000	305,907,000
Regulatory Liability For Income Taxes Net							985,823,000	0
Protected Excess ADIT Under H.R. 1							554,000,000
Unprotected Excess ADIT Under H.R. 1							467,000,000
Income Tax Expense(Benefit) Related to Excess ADIT							3,000,000
Entergy Louisiana [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates							575,800,000	473,300,000	692,700,000				61,600,000
Accrued income tax interest and penalties							14,100,000	8,400,000	9,300,000
Regulatory Liabilities							32,400,000	53,900,000					16,100,000
Proceeds from LURC											$ 148,600,000
Proceed from loan by LCDA to corporation LURC											$ 148,600,000
Deferred Income Taxes and Tax Credits							575,804,000	178,549,000	97,461,000
Income tax benefit resulting from 2006-2007 audit					11,000,000
Regulatory Liability, Noncurrent							761,059,000	880,974,000
Regulatory Liability Net Of Tax													9,900,000
Unrecognized Tax Benefits Impacting Effective Tax Rate from Vidalia PPA													$ 74,500,000
Noncash Capital Contribution from Parent							0	0	267,826,000
Change in accounting method for tax purposes, effect of change on taxable income									2,200,000,000
Deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements								2,200,000,000
Regulatory Liability For Income Taxes Net							725,368,000	0
Protected Excess ADIT Under H.R. 1							782,000,000
Unprotected Excess ADIT Under H.R. 1							410,000,000
Income Tax Expense(Benefit) Related to Excess ADIT							(217,000,000)
Entergy Mississippi [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates							0	0	8,100,000
Accrued income tax interest and penalties							1,000,000	800,000	400,000
Deferred Income Taxes and Tax Credits							84,816,000	60,986,000	18,673,000
Regulatory Liability For Income Taxes Net							411,011,000	0
Protected Excess ADIT Under H.R. 1							274,000,000
Unprotected Excess ADIT Under H.R. 1							162,000,000
Income Tax Expense(Benefit) Related to Excess ADIT							(3,000,000)
Entergy New Orleans [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates							31,700,000	33,600,000	50,700,000
Accrued income tax interest and penalties							2,100,000	1,500,000	1,800,000
Deferred Income Taxes and Tax Credits							64,036,000	140,283,000	22,180,000
Regulatory Liability For Income Taxes Net							119,259,000	9,074,000
Protected Excess ADIT Under H.R. 1							71,000,000
Unprotected Excess ADIT Under H.R. 1							37,000,000
Income Tax Expense(Benefit) Related to Excess ADIT							(6,000,000)
Deductible temporary difference related to election to mark-to-market Unit Power Sales agreement for tax purposes							1,100,000,000
Entergy Texas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates							4,400,000	7,000,000	5,200,000
Accrued income tax interest and penalties							400,000	1,200,000	1,200,000
Deferred Income Taxes and Tax Credits							42,119,000	20,794,000	(23,292,000)
Regulatory Liability, Noncurrent							6,850,000	8,502,000
Regulatory Liability For Income Taxes Net							412,620,000	0
Protected Excess ADIT Under H.R. 1							276,000,000
Unprotected Excess ADIT Under H.R. 1							198,000,000
Income Tax Expense(Benefit) Related to Excess ADIT							(3,000,000)
System Energy [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates							0	0	700,000
Accrued income tax interest and penalties							8,500,000	3,700,000	700,000
Deferred Income Taxes and Tax Credits							7,827,000	99,531,000	200,797,000
Income tax benefit resulting from 2006-2007 audit					$ 1,000,000
Regulatory Liability, Noncurrent							455,991,000	370,862,000
Change in accounting method for tax purposes, effect of change on taxable income									1,200,000,000
Regulatory Liability For Income Taxes Net							246,122,000	$ 0
Protected Excess ADIT Under H.R. 1							217,000,000
Unprotected Excess ADIT Under H.R. 1							76,000,000
Income Tax Expense(Benefit) Related to Excess ADIT							$ 0
Hurricane Rita [Member] | Entergy Gulf States Louisiana [Member]
Income Taxes [Line Items]
Proceeds from LURC			$ 274,700,000
Proceed from loan by LCDA to corporation LURC			$ 274,700,000
Hurricane Rita [Member] | Entergy Louisiana [Member]
Income Taxes [Line Items]
Proceeds from LURC				$ 679,000,000
Proceed from loan by LCDA to corporation LURC				$ 679,000,000
Member's Equity [Member] | Entergy Louisiana [Member]
Income Taxes [Line Items]
Noncash Capital Contribution from Parent									$ 267,826,000