Risk Management and Fair Values (Assets And Liabilities At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Assets at fair value on a recurring basis
Temporary cash investments		$ 1,148.0	$ 725.0
Assets other than temporary cash investments			7,212.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		8,797.0	8,414.0
Financial and Nonfinancial Liabilities, Fair Value Disclosure			76.0
Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		1.0	6.0
Power Contracts Liabilities [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis			70.0
Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		577.0	526.0
Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		2,619.0	2,550.0
Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3,920.0	4,136.0
Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		75.0	5.0
Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		398.0	406.0
Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		52.0	45.0
Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		8.0	21.0
Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,148.0	725.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		3,259.0	2,827.0
Financial and Nonfinancial Liabilities, Fair Value Disclosure			6.0
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	6.0
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		577.0	526.0
Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1,084.0	1,125.0
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		398.0	406.0
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		52.0	45.0
Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [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
Assets, Fair Value Disclosure		1,535.0	1,425.0
Financial and Nonfinancial Liabilities, Fair Value Disclosure			0.0
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		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		1,535.0	1,425.0
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]
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
Assets, Fair Value Disclosure		83.0	26.0
Financial and Nonfinancial Liabilities, Fair Value Disclosure			70.0
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			70.0
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		75.0	5.0
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]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		8.0	21.0
Entergy Mississippi [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.3	4.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		33.3	38.6
Entergy Mississippi [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		0.2	1.2
Entergy Mississippi [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		32.1	32.0
Entergy Mississippi [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.9	2.1
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.3	4.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		32.4	36.5
Entergy Mississippi [Member] | 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		0.2	1.2
Entergy Mississippi [Member] | 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		32.1	32.0
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [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]
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]
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]
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]
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]
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		0.9	2.1
Entergy Mississippi [Member] | 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
Entergy Mississippi [Member] | 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
Entergy Mississippi [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.9	2.1
Entergy Louisiana [Member]
Assets at fair value on a recurring basis
Temporary cash investments		561.9	30.1
Assets other than temporary cash investments			1,312.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		2,164.8	1,643.9
Entergy Louisiana [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		1.2	5.0
Entergy Louisiana [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	12.2	15.2
Entergy Louisiana [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	516.3	493.8
Entergy Louisiana [Member] | Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	775.9	803.1
Entergy Louisiana [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		285.6	289.5
Entergy Louisiana [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		9.5	2.0
Entergy Louisiana [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.4	10.2
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		561.9	30.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,014.8	480.1
Entergy Louisiana [Member] | 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		1.2	5.0
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	12.2	15.2
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	145.6	143.3
Entergy Louisiana [Member] | 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		285.6	289.5
Entergy Louisiana [Member] | 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		9.5	2.0
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [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]
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		370.7	350.5
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	370.7	350.5
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [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]
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		3.4	10.2
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	0.0	0.0
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	0.0	0.0
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | 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
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.4	10.2
Entergy Arkansas [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments			944.9
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		945.4	954.0
Entergy Arkansas [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	3.6	11.7
Entergy Arkansas [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	350.8	348.2
Entergy Arkansas [Member] | Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	581.3	585.0
Entergy Arkansas [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments			2.4
Entergy Arkansas [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		7.9	3.7
Entergy Arkansas [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1.8	3.0
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		122.8	133.6
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	3.6	11.7
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	111.3	115.8
Entergy Arkansas [Member] | 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			2.4
Entergy Arkansas [Member] | 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		7.9	3.7
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [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]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		239.5	232.4
Entergy Arkansas [Member] | 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
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	239.5	232.4
Entergy Arkansas [Member] | 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
Entergy Arkansas [Member] | 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
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [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]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1.8	3.0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	0.0	0.0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	0.0	0.0
Entergy Arkansas [Member] | 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
Entergy Arkansas [Member] | 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
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1.8	3.0
Entergy New Orleans [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1.3	32.7
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		86.6	118.3
Entergy New Orleans [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis			0.2
Entergy New Orleans [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		79.8	81.9
Entergy New Orleans [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		4.8	1.5
Entergy New Orleans [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.7	2.2
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1.3	32.7
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		85.9	116.1
Entergy New Orleans [Member] | 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			0.2
Entergy New Orleans [Member] | 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		79.8	81.9
Entergy New Orleans [Member] | 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		4.8	1.5
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [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]
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]
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]
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]
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]
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]
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		0.7	2.2
Entergy New Orleans [Member] | 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
Entergy New Orleans [Member] | 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
Entergy New Orleans [Member] | 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
Entergy New Orleans [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.7	2.2
Entergy Texas [Member]
Assets at fair value on a recurring basis
Temporary cash investments		39.0	115.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		70.1	156.6
Entergy Texas [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		29.7	37.7
Entergy Texas [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1.4	3.4
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		39.0	115.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		68.7	153.2
Entergy Texas [Member] | 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		29.7	37.7
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [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]
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 Texas [Member] | 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
Entergy Texas [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [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]
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		1.4	3.4
Entergy Texas [Member] | 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
Entergy Texas [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1.4	3.4
System Energy [Member]
Assets at fair value on a recurring basis
Temporary cash investments		278.7	287.1
Assets other than temporary cash investments			905.7
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,174.9	1,192.8
System Energy [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	2.3	3.1
System Energy [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	325.6	330.5
System Energy [Member] | Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	568.3	572.1
System Energy [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		278.7	287.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		453.5	477.4
System Energy [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	2.3	3.1
System Energy [Member] | Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	172.5	187.2
System Energy [Member] | 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
Assets, Fair Value Disclosure		153.1	143.3
System Energy [Member] | 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
System Energy [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	153.1	143.3
System Energy [Member] | 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
Assets, Fair Value Disclosure		0.0	0.0
System Energy [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [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]
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.(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.