Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended				3 Months Ended			12 Months Ended
	Jun. 30, 2016	Aug. 31, 2015	Aug. 31, 2008	Jul. 31, 2008	Dec. 31, 2016	Mar. 31, 2015	Dec. 31, 2009	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012	Oct. 31, 2015
Income Taxes [Line Items]
Reduction in taxable income relating to 2009 CAM settlement							$ 5,700,000
Valuation allowance on the deferred tax assets related to state net operating loss carryovers					$ 62,000			$ 62,000	$ 46,000
Unrecognized tax benefits if recognized, would lower the effective income tax rates	$ 63,500				1,240,000			1,240,000	955,000	$ 516,000
Remaining balances of unrecognized tax benefits, effective income tax rates					2,670,000			2,670,000	1,657,000	4,221,000
Accrued income tax interest and penalties					30,000			30,000	27,000	127,000
Regulatory Liabilities												$ 107,000
Adjustment 2009 CAM											$ 9,300,000
Deferred Income Taxes and Tax Credits								(836,257)	(820,350)	596,935
Deferred Tax Assets, Valuation Allowance					104,277			104,277	91,532
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					59,079			59,079	68,204			334,000
Regulatory Liability, Noncurrent					1,572,929			1,572,929	1,414,898			107,000
Regulatory Liability Net Of Tax												$ 66,000
Valuation allowances on deferred tax assets related to state jurisdictions					42,300			42,300	45,500
Reduction in income tax expense related to permanent difference for nuclear decommissioning liability, net of unrecognized tax benefits								238,000
Entergy Arkansas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					3,600			3,600	4,500	2,600
Accrued income tax interest and penalties					1,400			1,400	1,300	17,000
Deferred Income Taxes and Tax Credits								201,219	(4,330)	130,132
Income tax benefit resulting from 2006-2007 audit						4,000
Other					174			174	128
Regulatory Liability, Noncurrent					305,907			305,907	242,913
Entergy Louisiana [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates	61,600				473,300			473,300	692,700	267,300
Accrued income tax interest and penalties					8,400			8,400	9,300	22,200
Regulatory Liabilities	16,100				53,900			53,900	68,300
Proceeds from LURC	148,600
Proceed from loan by LCDA to corporation LURC	148,600
Deferred Income Taxes and Tax Credits								178,549	97,461	248,686
Income tax benefit resulting from 2006-2007 audit						11,000
Other					17,110			17,110	21,982
Regulatory Liability, Noncurrent					880,974			880,974	818,623
Regulatory Liability Net Of Tax	9,900
Unrecognized Tax Benefits Impacting Effective Tax Rate from Vidalia PPA	$ 74,500
Noncash Capital Contribution from Parent								0	267,826	0
Change in accounting method for tax purposes, effect of change on taxable income					2,200,000
Deductible temporary difference related to election to mark-to-market certain power purchase and sales agreements								2,200,000
Entergy Mississippi [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					0			0	8,100	3,900
Accrued income tax interest and penalties					800			800	400	2,800
Deferred Income Taxes and Tax Credits								60,986	18,673	32,472
Other					1,152			1,152	1,995
Entergy New Orleans [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					33,600			33,600	50,700	50,700
Accrued income tax interest and penalties					1,500			1,500	1,800	1,300
Deferred Income Taxes and Tax Credits								140,283	22,180	24,380
Other					496			496	316
Entergy Texas [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					7,000			7,000	5,200	10,500
Accrued income tax interest and penalties					1,200			1,200	1,200	1,000
Deferred Income Taxes and Tax Credits								20,794	(23,292)	2,829
Other					2,955			2,955	1,672
Regulatory Liability, Noncurrent					8,502			8,502	6,396
System Energy [Member]
Income Taxes [Line Items]
Unrecognized tax benefits if recognized, would lower the effective income tax rates					0			0	700	3,700
Accrued income tax interest and penalties					3,700			3,700	700	23,800
Deferred Income Taxes and Tax Credits								99,531	200,797	$ 79,835
Income tax benefit resulting from 2006-2007 audit						$ 1,000
Other					0			0	0
Regulatory Liability, Noncurrent					370,862			$ 370,862	$ 337,424
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