Risk Management and Fair Values (Assets And Liabilities At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Dec. 31, 2015		Dec. 31, 2014
Assets at fair value on a recurring basis
Available-for-sale Securities		$ 5,350.0		$ 5,371.0
Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,287.0		1,291.0
Total		7,330.0		7,332.0
Liabilities at fair value on a recurring basis
Total		15.0		22.0
Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		9.0		20.0
Power Contracts Liabilities [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		6.0		2.0
Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	3,195.0		3,286.0
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	2,155.0		2,085.0
Power Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		195.0		217.0
Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		50.0		44.0
Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		425.0		362.0
Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		23.0		47.0
Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,287.0		1,291.0
Total		3,291.0		3,029.0
Liabilities at fair value on a recurring basis
Total		9.0		20.0
Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		9.0		20.0
Fair Value Inputs Level 1 [Member] | Power Contracts Liabilities [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Fair Value Inputs Level 1 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	468.0		452.0
Fair Value Inputs Level 1 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	1,061.0		880.0
Fair Value Inputs Level 1 [Member] | Power Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 1 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		50.0		44.0
Fair Value Inputs Level 1 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		425.0		362.0
Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		3,821.0		4,039.0
Liabilities at fair value on a recurring basis
Total		0.0		0.0
Fair Value Inputs Level 2 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Fair Value Inputs Level 2 [Member] | Power Contracts Liabilities [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Fair Value Inputs Level 2 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	2,727.0		2,834.0
Fair Value Inputs Level 2 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	1,094.0		1,205.0
Fair Value Inputs Level 2 [Member] | Power Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 2 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 2 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		218.0		264.0
Liabilities at fair value on a recurring basis
Total		6.0		2.0
Fair Value Inputs Level 3 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Fair Value Inputs Level 3 [Member] | Power Contracts Liabilities [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		6.0		2.0
Fair Value Inputs Level 3 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	0.0		0.0
Fair Value Inputs Level 3 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities	[1]	0.0		0.0
Fair Value Inputs Level 3 [Member] | Power Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		195.0		217.0
Fair Value Inputs Level 3 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 3 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Fair Value Inputs Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		23.0		47.0
Entergy New Orleans [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		87.8		41.4
Total		174.9		63.5
Entergy New Orleans [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.5		0.9
Entergy New Orleans [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		4.6
Entergy New Orleans [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		81.0		18.0
Entergy New Orleans [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		1.5		4.1
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		87.8		41.4
Total		173.4		59.4
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.5		0.9
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		4.6
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		81.0		18.0
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 2 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 2 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 2 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		1.5		4.1
Entergy New Orleans [Member] | Fair Value Inputs Level 3 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 3 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 3 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy New Orleans [Member] | Fair Value Inputs Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		1.5		4.1
Entergy Mississippi [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		144.2		60.4
Total		188.3		105.6
Entergy Mississippi [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		1.3		2.8
Entergy Mississippi [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		41.7		41.8
Entergy Mississippi [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		2.4		3.4
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		144.2		60.4
Total		185.9		102.2
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		1.3		2.8
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		41.7		41.8
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 2 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 2 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		2.4		3.4
Entergy Mississippi [Member] | Fair Value Inputs Level 3 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 3 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Mississippi [Member] | Fair Value Inputs Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		2.4		3.4
Entergy Texas [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				28.7
Total		40.4		78.2
Entergy Texas [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		38.2		37.2
Entergy Texas [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		2.2		12.3
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				28.7
Total		38.2		65.9
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		38.2		37.2
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Texas [Member] | Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				0.0
Total		0.0		0.0
Entergy Texas [Member] | Fair Value Inputs Level 2 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Texas [Member] | Fair Value Inputs Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Texas [Member] | Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				0.0
Total		2.2		12.3
Entergy Texas [Member] | Fair Value Inputs Level 3 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Texas [Member] | Fair Value Inputs Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		2.2		12.3
Entergy Arkansas [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		771.3		769.9
Entergy Arkansas [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				208.0
Total		795.6	[1]	994.9
Entergy Arkansas [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		467.4	[1]	487.3
Entergy Arkansas [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		303.9	[1]	282.6
Entergy Arkansas [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		4.2	[1]	4.1
Entergy Arkansas [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		12.2	[1]	12.2
Entergy Arkansas [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		7.9	[1]	0.7
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				208.0
Total		129.9	[1]	303.7
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		3.0	[1]	7.2
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		110.5	[1]	72.2
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		4.2	[1]	4.1
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		12.2	[1]	12.2
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				0.0
Total		657.8	[1]	690.5
Entergy Arkansas [Member] | Fair Value Inputs Level 2 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		464.4	[1]	480.1
Entergy Arkansas [Member] | Fair Value Inputs Level 2 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		193.4	[1]	210.4
Entergy Arkansas [Member] | Fair Value Inputs Level 2 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 2 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments				0.0
Total		7.9	[1]	0.7
Entergy Arkansas [Member] | Fair Value Inputs Level 3 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 3 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 3 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 3 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0	[1]	0.0
Entergy Arkansas [Member] | Fair Value Inputs Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		7.9	[1]	0.7
Entergy Louisiana [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		1,042.3		1,021.3
Entergy Louisiana [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		34.8		266.7
Total		1,379.2		1,606.7
Entergy Louisiana [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		7.0		15.8
Entergy Louisiana [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		632.4		635.5
Entergy Louisiana [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		409.9		385.8
Entergy Louisiana [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		3.2		3.1
Entergy Louisiana [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		290.4		290.1
Entergy Louisiana [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		8.5		25.5
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		34.8		266.7
Total		496.6		725.8
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		7.0		15.8
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		7.1		15.3
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		161.1		150.6
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		3.2		3.1
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		290.4		290.1
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		874.1		855.4
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		625.3		620.2
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		248.8		235.2
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		8.5		25.5
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Escrow Accounts [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
Entergy Louisiana [Member] | Fair Value Inputs Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		8.5		25.5
System Energy [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		701.5		679.8
System Energy [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		222.0		222.4
Total		923.5		902.2
System Energy [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		423.7		424.5
System Energy [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		277.8		255.3
System Energy [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		222.0		222.4
Total		442.4		418.6
System Energy [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		1.8		2.0
System Energy [Member] | Fair Value Inputs Level 1 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		218.6		194.2
System Energy [Member] | Fair Value Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		481.1		483.6
System Energy [Member] | Fair Value Inputs Level 2 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		421.9		422.5
System Energy [Member] | Fair Value Inputs Level 2 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		59.2		61.1
System Energy [Member] | Fair Value Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0		0.0
Total		0.0		0.0
System Energy [Member] | Fair Value Inputs Level 3 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		0.0		0.0
System Energy [Member] | Fair Value Inputs Level 3 [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Available-for-sale Securities		$ 0.0		$ 0.0

[1] The decommissioning trust funds hold equity and fixed income securities. Equity securities are invested to approximate the returns of major market indices. Fixed income securities are held in various governmental and corporate securities. See Note 17 to the financial statements for additional information on the investment portfolios.