Risk Management and Fair Values (Assets And Liabilities At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Assets at fair value on a recurring basis
Assets other than temporary cash investments		$ 5,671.0	$ 5,350.0
Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,206.0	1,287.0
Liabilities at fair value on a recurring basis
Total			15.0
Assets, Fair Value Disclosure		7,490.0	7,330.0
Gas Hedge Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		1.0	9.0
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
Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	451.0	468.0
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	2,291.0	2,155.0
Common trust funds valued using Net Asset Value [Domain] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1],[2]	2,929.0	2,727.0
Power Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		95.0	195.0
Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		433.0	425.0
Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		54.0	50.0
Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		31.0	23.0
Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,206.0	1,287.0
Liabilities at fair value on a recurring basis
Total			9.0
Assets, Fair Value Disclosure		3,160.0	3,291.0
Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		1.0	9.0
Fair Value Inputs Level 1 [Member] | Power Contracts Liabilities [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis			0.0
Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	451.0	468.0
Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	1,016.0	1,061.0
Fair Value Inputs Level 1 [Member] | Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value Inputs Level 1 [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		433.0	425.0
Fair Value Inputs Level 1 [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		54.0	50.0
Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 2 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0	0.0
Liabilities at fair value on a recurring basis
Total			0.0
Assets, Fair Value Disclosure		1,275.0	1,094.0
Fair Value, Inputs, Level 2 [Member] | Gas Hedge Contracts [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]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis			0.0
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	0.0	0.0
Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	1,275.0	1,094.0
Fair Value, Inputs, Level 2 [Member] | Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 2 [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 2 [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 3 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0	0.0
Liabilities at fair value on a recurring basis
Total			6.0
Assets, Fair Value Disclosure		126.0	218.0
Fair Value, Inputs, Level 3 [Member] | Gas Hedge Contracts [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]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis			6.0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		95.0	195.0
Fair Value, Inputs, Level 3 [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		31.0	23.0
Entergy Louisiana [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1,124.8	1,042.3
Entergy Louisiana [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		57.6	34.8
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,510.1	1,379.2
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		0.4	7.0
Entergy Louisiana [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[3]	5.7	7.1
Entergy Louisiana [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[3]	440.1	409.9
Entergy Louisiana [Member] | Common trust funds valued using Net Asset Value [Domain] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	679.0	625.3
Entergy Louisiana [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		305.5	290.4
Entergy Louisiana [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		9.8	3.2
Entergy Louisiana [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		12.4	8.5
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		57.6	34.8
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		510.1	496.6
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		0.4	7.0
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
Assets other than temporary cash investments	[3]	5.7	7.1
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
Assets other than temporary cash investments	[3]	131.5	161.1
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		305.5	290.4
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
Assets other than temporary cash investments		9.8	3.2
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
Assets other than temporary cash investments		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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		308.6	248.8
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
Assets other than temporary cash investments	[3]	0.0	0.0
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
Assets other than temporary cash investments	[3]	308.6	248.8
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
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
Assets other than temporary cash investments		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
Assets other than temporary cash investments		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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		12.4	8.5
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
Assets other than temporary cash investments	[3]	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
Assets other than temporary cash investments	[3]	0.0	0.0
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		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
Assets other than temporary cash investments		12.4	8.5
Entergy Arkansas [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		823.8	771.3
Entergy Arkansas [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		846.7	795.6
Entergy Arkansas [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[3]	3.7	3.0
Entergy Arkansas [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[3]	318.9	303.9
Entergy Arkansas [Member] | Common trust funds valued using Net Asset Value [Domain] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	501.2	464.4
Entergy Arkansas [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		7.1	12.2
Entergy Arkansas [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		7.7	4.2
Entergy Arkansas [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		8.1	7.9
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		121.6	129.9
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
Assets other than temporary cash investments	[3]	3.7	3.0
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
Assets other than temporary cash investments	[3]	103.1	110.5
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		7.1	12.2
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
Assets other than temporary cash investments		7.7	4.2
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
Assets other than temporary cash investments		0.0	0.0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		215.8	193.4
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
Assets other than temporary cash investments	[3]	0.0	0.0
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
Assets other than temporary cash investments	[3]	215.8	193.4
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	0.0
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
Assets other than temporary cash investments		0.0	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
Assets other than temporary cash investments		0.0	0.0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		8.1	7.9
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
Assets other than temporary cash investments	[3]	0.0	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
Assets other than temporary cash investments	[3]	0.0	0.0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0	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
Assets other than temporary cash investments		0.0	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
Assets other than temporary cash investments		8.1	7.9
Entergy Mississippi [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		307.3	144.2
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		343.1	188.3
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		0.1	1.3
Entergy Mississippi [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		31.8	41.7
Entergy Mississippi [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		4.0	2.4
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		307.3	144.2
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		339.1	185.9
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		0.1	1.3
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		31.8	41.7
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
Assets other than temporary cash investments		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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		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] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		4.0	2.4
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] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		4.0	2.4
Entergy New Orleans [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		37.2	87.8
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		132.3	174.9
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
Entergy New Orleans [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		88.4	81.0
Entergy New Orleans [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		5.1	4.6
Entergy New Orleans [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1.6	1.5
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		37.2	87.8
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		130.7	173.4
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
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		88.4	81.0
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
Assets other than temporary cash investments		5.1	4.6
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
Assets other than temporary cash investments		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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		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
Entergy New Orleans [Member] | Fair Value, Inputs, Level 2 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		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
Assets other than temporary cash investments		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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1.6	1.5
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
Entergy New Orleans [Member] | Fair Value, Inputs, Level 3 [Member] | Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		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
Assets other than temporary cash investments		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
Assets other than temporary cash investments		1.6	1.5
Entergy Texas [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		36.5	40.4
Entergy Texas [Member] | Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		31.4	38.2
Entergy Texas [Member] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		5.1	2.2
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		31.4	38.2
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
Assets other than temporary cash investments		31.4	38.2
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
Assets other than temporary cash investments		0.0	0.0
Entergy Texas [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		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
Assets other than temporary cash investments		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
Assets other than temporary cash investments		0.0	0.0
Entergy Texas [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		5.1	2.2
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
Assets other than temporary cash investments		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
Assets other than temporary cash investments		5.1	2.2
System Energy [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		764.9	701.5
System Energy [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		190.2	222.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		955.1	923.5
System Energy [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	1.2	1.8
System Energy [Member] | Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	308.6	277.8
System Energy [Member] | Common trust funds valued using Net Asset Value [Domain] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	455.1	421.9
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		190.2	222.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		437.9	442.4
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
Assets other than temporary cash investments	[1]	1.2	1.8
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
Assets other than temporary cash investments	[1]	246.5	218.6
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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		62.1	59.2
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
Assets other than temporary cash investments	[1]	0.0	0.0
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
Assets other than temporary cash investments	[1]	62.1	59.2
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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		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
Assets other than temporary cash investments	[1]	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
Assets other than temporary cash investments	[1]	$ 0.0	$ 0.0

[1] (a)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 9 to the financial statements herein for additional information on the investment portfolios.

[2] (b)Common trust funds are not publicly quoted, and are valued by the fund administrators using net asset value as a practical expedient. Accordingly, these funds are not assigned a level in the fair value table. The fund administrator of these investments allows daily trading at the net asset value and trades settle at a later date.The following table sets forth a reconciliation of changes in the net assets (liabilities) for the fair value of derivatives classified as Level 3 in the fair value hierarchy for the three months ended September 30, 2016 and 2015: 2016 2015 Power Contracts FTRs Power Contracts FTRs (In Millions)Balance as of July 1,$66 $46 $204 $67Total gains (losses) for the period (a) Included in earnings6 — (2) —Included in OCI70 — 49 —Included as a regulatory liability/asset— 22 — 31Settlements(47) (37) (88) (51)Balance as of September 30,$95 $31 $163 $47

[3] (a)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 9 to the financial statements herein for additional information on the investment portfolios.(b)Common trust funds are not publicly quoted, and are valued by the fund administrators using net asset value as a practical expedient. Accordingly, these funds are not assigned a level in the fair value table. The fund administrator of these investments allows daily trading at the net asset value and trades settle at a later date.