Risk Management and Fair Values (Assets And Liabilities At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Jun. 30, 2018	Dec. 31, 2017
Assets at fair value on a recurring basis
Temporary cash investments		$ 758.0	$ 725.0
Assets other than temporary cash investments			7,212.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		8,466.0	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			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
Equity Securities, FV-NI		562.0	526.0
Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		2,620.0	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		4,035.0	4,136.0
Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		8.0	5.0
Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		399.0	406.0
Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		40.0	45.0
Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		41.0	21.0
Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		758.0	725.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		2,826.0	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			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	0.0
Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI		562.0	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		1,064.0	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		399.0	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		40.0	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		1,556.0	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
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	0.0
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI		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		1,556.0	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		49.0	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
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		33.0	70.0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI		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		8.0	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		41.0	21.0
Entergy Mississippi [Member]
Assets at fair value on a recurring basis
Temporary cash investments			4.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		37.1	38.6
Entergy Mississippi [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis			1.2
Entergy Mississippi [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		32.2	32.0
Entergy Mississippi [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		4.4	2.1
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments			4.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		32.7	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			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		32.2	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
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
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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		4.4	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
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		4.4	2.1
Entergy Louisiana [Member]
Assets at fair value on a recurring basis
Temporary cash investments		28.8	30.1
Assets other than temporary cash investments			1,312.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,674.7	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			5.0
Entergy Louisiana [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[1]	18.1	15.2
Entergy Louisiana [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	513.8	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]	803.0	803.1
Entergy Louisiana [Member] | Storm Reserve Escrow Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		286.7	289.5
Entergy Louisiana [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.4	2.0
Entergy Louisiana [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		18.2	10.2
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		28.8	30.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		481.2	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			5.0
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[1]	18.1	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]	141.5	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		286.7	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		3.4	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		372.3	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
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[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]	372.3	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		18.2	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
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[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		18.2	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		1,201.8	954.0
Entergy Arkansas [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[1]	11.3	11.7
Entergy Arkansas [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	341.7	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]	601.4	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		4.1	3.7
Entergy Arkansas [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		10.5	3.0
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		337.3	133.6
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[1]	11.3	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]	89.1	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		4.1	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		252.6	232.4
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[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]	252.6	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		10.5	3.0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[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		10.5	3.0
Entergy New Orleans [Member]
Assets at fair value on a recurring basis
Temporary cash investments			32.7
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		84.6	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		80.1	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		1.5	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		3.0	2.2
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments			32.7
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		81.6	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		80.1	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		1.5	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
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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		3.0	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		3.0	2.2
Entergy Texas [Member]
Assets at fair value on a recurring basis
Temporary cash investments		40.4	115.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		76.3	156.6
Entergy Texas [Member] | Securitization Recovery Trust Account [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		31.2	37.7
Entergy Texas [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		4.7	3.4
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		40.4	115.5
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		71.6	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		31.2	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		4.7	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		4.7	3.4
System Energy [Member]
Assets at fair value on a recurring basis
Temporary cash investments		258.7	287.1
Assets other than temporary cash investments			905.7
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,173.1	1,192.8
System Energy [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[1]	5.0	3.1
System Energy [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments	[1]	324.2	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]	585.2	572.1
System Energy [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		258.7	287.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		442.4	477.4
System Energy [Member] | Fair Value Inputs Level 1 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[1]	5.0	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]	178.7	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		145.5	143.3
System Energy [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets at fair value on a recurring basis
Equity Securities, FV-NI	[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]	145.5	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
Equity Securities, FV-NI	[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
Fair Value, Measurements, Recurring [Member] | Power Contracts Liabilities [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		33.0
Fair Value, Measurements, Recurring [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.0
Fair Value, Measurements, Recurring [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Entergy Mississippi [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.5
Fair Value, Measurements, Recurring [Member] | Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.5
Fair Value, Measurements, Recurring [Member] | Entergy Mississippi [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Entergy Mississippi [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Entergy Louisiana [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		2.7
Fair Value, Measurements, Recurring [Member] | Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		2.7
Fair Value, Measurements, Recurring [Member] | Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Entergy Arkansas [Member]
Assets at fair value on a recurring basis
Temporary cash investments		232.8
Fair Value, Measurements, Recurring [Member] | Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		232.8
Fair Value, Measurements, Recurring [Member] | Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		0.0
Fair Value, Measurements, Recurring [Member] | Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		$ 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.