Commitments and Contingencies (Entergy Corporation, Entergy Arkansas, Entergy Gulf States Louisiana, Entergy Louisiana, Entergy Mississippi, Entergy New Orleans, Entergy Texas, and System Energy) (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2011 NuclearReactor Y Ratio	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2031
Commitments and Contingencies (Textual) [Abstract]
Payments made under Purchased Power Agreement	$ 185,600,000	$ 216,500,000	$ 204,900,000
Required energy for the production of Vidalia project in percentage	94.00%
Estimated Payments under Purchased Power Agreement	172,100,000			2,500,000,000
Credit rates agreed by subsidiary for each year under settlement related to tax benefits from the tax treatment of Purchased Power Agreement	11,000,000
Number of years for which credit rates agreed by subsidiary under settlement related to tax benefits from the tax treatment of Purchased Power Agreement	10
Resulted credit rate with interest by IRS settlement	11,300,000
Insurance coverage for public liability by American Nuclear Insurers	375,000,000
Maximum retrospective insurance premium obligation per reactor per incident	117,500,000
Maximum total contingent obligation per incident	1,300,000,000
Maximum retrospective insurance premium obligation excluding surcharge per reactor per incident	111,900,000
Surcharge on maximum retrospective premium	5.00%
Rate of maximum retrospective premium per year per nuclear power reactor	17,500,000
Number of nuclear reactor included in secondary financial protection program	104
Total premium for reactor under secondary financial protection Program	12,200,000,000
Ownership percentage by a non affiliated company in Variable interest entity	10.00%
Number of operative nuclear power reactors under Entergy Wholesale Commodities business	6
ANI combined with Secondary Financial Protection coverage	12,600,000,000
Property insurance minimum requirement per site for nuclear power plant licensees.	1,060,000,000
Maximum recovery nuclear insurance policies	3,240,000,000
Excess of existing coverage for a terrorist event	100,000,000,000
Maximum Conventional property insurance Coverage on an each and every loss basis	400,000,000
Primary layer in property insurance excess of self insured retention	65,000,000
Property insurance excess layer in excess of primary layer	335,000,000
Payment for additional coverage per occurrence	65,000,000
Purchase of terrorism insurance coverage	300,000,000
Amount of additional insurance coverage per occurrence	20,000,000
Amount of remaining Benefits of tax credit by crediting rate payers	20,235,000
Maximum period up to which remaining benefit of tax accounting election shared	15 years
Applicable deduction for insurance premium	$100,000 to $250,000, except for properties that are damaged by flooding and properties whose values are greater than $20 million; these properties have a $500,000 deductible
Additional insurance coverage minimum	100,000
Additional insurance coverage maximum	250,000
value of properties damaged by natural calamities	20,000,000
Amount deductibles for properties damaged by natural calamities	500,000
Ratio of debt to liabilities and equity	70.00%
Ratio of adjusted net income to interest expense	1.50
Waterford Three [Member]
Loss Contingencies [Line Items]
Weekly indemnity	2,950,000
Maximum indemnity	413,000,000
Waiting period	26
Grand Gulf [Member]
Loss Contingencies [Line Items]
Weekly indemnity	400,000
Maximum indemnity	56,000,000
Waiting period	26
Indian Point Two Indian Point Three And Palisades [Member]
Loss Contingencies [Line Items]
Weekly indemnity	4,500,000
Maximum indemnity	490,000,000
Waiting period	12
Fitz Patrick And Pilgrim [Member]
Loss Contingencies [Line Items]
Weekly indemnity	4,000,000
Maximum indemnity	490,000,000
Waiting period	12
Vermont Yankee [Member]
Loss Contingencies [Line Items]
Weekly indemnity	3,500,000
Maximum indemnity	435,000,000
Waiting period	12
Utility [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	1,600,000,000
Property insurance deductible for damage from a windstorm	10 million per occurrence plus 10% of amount above $10 million
Property insurance of damage from natural calamities	10,000,000
Additional deductible percentage	10.00%
Entergy Wholesale Commodities [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	1,115,000,000
Property insurance deductible for damage from a windstorm	10 million per occurrence plus 10% of amount above $10 million
Property insurance of damage from natural calamities	10,000,000
Additional deductible percentage	10.00%
Primary Layer [Member] | Utility [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	500,000,000
Primary Layer [Member] | Entergy Wholesale Commodities [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	500,000,000
Excess layer [Member] | Utility [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	750,000,000
Excess layer [Member] | Entergy Wholesale Commodities [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	615,000,000
Blanket Layer [Member] | Utility [Member]
Loss Contingencies [Line Items]
Property Insurance insured amount per occurrence	350,000,000
Turbine And Generator Damage [Member] | Utility [Member]
Loss Contingencies [Line Items]
Property Insurance deductibles per occurrence	2,500,000
Turbine And Generator Damage [Member] | Entergy Wholesale Commodities [Member]
Loss Contingencies [Line Items]
Property Insurance deductibles per occurrence	2,500,000
Other Than Turbine And Generator Damage [Member] | Utility [Member]
Loss Contingencies [Line Items]
Property Insurance deductibles per occurrence	2,500,000
Other Than Turbine And Generator Damage [Member] | Entergy Wholesale Commodities [Member]
Loss Contingencies [Line Items]
Property Insurance deductibles per occurrence	2,500,000
Natural Perils From Earthquake Tsunami Flood Ice Storm And Tornado [Member]
Loss Contingencies [Line Items]
Maximum Conventional property insurance Coverage on an annual aggregate basis	400,000,000
Other Natural Perils [Member]
Loss Contingencies [Line Items]
Maximum Conventional property insurance Coverage on an annual aggregate basis	125,000,000
Entergy New Orleans Gas Distribution System [Member]
Loss Contingencies [Line Items]
Maximum Conventional property insurance Coverage on an annual aggregate basis	50,000,000
Self-insured retention per occurrence for operational perils	35,000,000
Operational Perils [Member]
Loss Contingencies [Line Items]
Self-insured retention per occurrence for operational perils	20,000,000
Entergy Arkansas
Loss Contingencies [Line Items]
Number of licensed reactors	2
Entergy Gulf States Louisiana
Loss Contingencies [Line Items]
Number of licensed reactors	1
Entergy Louisiana [Member]
Loss Contingencies [Line Items]
Number of licensed reactors	1
Regulatory charges	$ 199,000,000
System Energy [Member]
Loss Contingencies [Line Items]
Number of licensed reactors	1