Risk Management and Fair Values (Assets And Liabilities At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Assets at fair value on a recurring basis
Assets other than temporary cash investments		$ 6,669.0	$ 5,724.0
Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,022.0	1,058.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		8,189.0	7,311.0
Power Contracts Liabilities [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		18.0	11.0
Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		512.0	480.0
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		2,230.0	2,213.0
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		3,927.0	3,031.0
Power Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		23.0	16.0
Storm Reserve Escrow Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		415.0	433.0
Securitization Recovery Trust Account [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		47.0	46.0
Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		5.0	13.0
Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		8.0	21.0
Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments		1,022.0	1,058.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		2,967.0	3,015.0
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
Assets other than temporary cash investments		512.0	480.0
Fair Value Inputs Level 1 [Member] | Debt Securities [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		966.0	985.0
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		415.0	433.0
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		47.0	46.0
Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		5.0	13.0
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
Assets, Fair Value Disclosure		1,264.0	1,228.0
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
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		1,264.0	1,228.0
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] | Gas Hedge Contracts Assets [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] | 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
Assets, Fair Value Disclosure		31.0	37.0
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		18.0	11.0
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		23.0	16.0
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] | Gas Hedge Contracts Assets [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] | Fixed Transmission Rights (FTRs) [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		8.0	21.0
Entergy Mississippi [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments			76.8
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		33.8	114.1
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	31.8
Entergy Mississippi [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.7	2.3
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		1.3	3.2
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			76.8
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		32.5	110.9
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	31.8
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		0.7	2.3
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
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] | 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] | Gas Hedge Contracts Assets [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
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1.3	3.2
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] | Gas Hedge Contracts Assets [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		1.3	3.2
Entergy Louisiana [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		1,190.1	1,140.7
Entergy Louisiana [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		64.7	163.9
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,563.6	1,632.5
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	[1]	7.6	13.9
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	[1]	439.5	424.8
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		743.0	702.0
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		292.5	305.7
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		8.4	2.8
Entergy Louisiana [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.8	10.9
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		4.1	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		64.7	163.9
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		509.0	629.5
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	[1]	7.6	13.9
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	[1]	132.0	132.3
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		292.5	305.7
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		8.4	2.8
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		3.8	10.9
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		307.5	292.5
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	[1]	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	[1]	307.5	292.5
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] | Gas Hedge Contracts Assets [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		4.1	8.5
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	[1]	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	[1]	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] | Gas Hedge Contracts Assets [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		4.1	8.5
Entergy Arkansas [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		867.7	834.7
Entergy Arkansas [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		881.1	851.3
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	[1]	6.1	3.6
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	[1]	310.0	309.3
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		551.6	521.8
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		4.7	7.1
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		7.8	4.1
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		0.9	5.4
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		125.3	127.3
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	[1]	6.1	3.6
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	[1]	106.7	112.5
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		4.7	7.1
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		7.8	4.1
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		203.3	196.8
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	[1]	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	[1]	203.3	196.8
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		0.9	5.4
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	[1]	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	[1]	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		0.9	5.4
Entergy New Orleans [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		55.0	103.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		146.4	194.6
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		86.3	88.6
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		4.6	1.7
Entergy New Orleans [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments			0.2
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		0.5	1.1
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		55.0	103.0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		145.9	193.5
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		86.3	88.6
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		4.6	1.7
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments			0.2
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] | 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] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments			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		0.5	1.1
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] | Gas Hedge Contracts Assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments			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		0.5	1.1
Entergy Texas [Member]
Assets at fair value on a recurring basis
Temporary cash investments			5.0
Entergy Texas [Member] | Fair Value, Measurements, Recurring [Member]
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		27.3	45.6
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		26.3	37.5
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		1.0	3.1
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Temporary cash investments			5.0
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		26.3	42.5
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		26.3	37.5
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]
Assets at fair value on a recurring basis
Temporary cash investments			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]
Assets at fair value on a recurring basis
Temporary cash investments			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		1.0	3.1
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		1.0	3.1
System Energy [Member]
Assets at fair value on a recurring basis
Assets other than temporary cash investments		816.0	780.5
System Energy [Member] | Fair Value, Measurements, Recurring [Member]
Assets at fair value on a recurring basis
Temporary cash investments		239.6	245.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		1,055.6	1,025.6
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]	8.1	0.3
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]	307.0	306.6
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]	500.9	473.6
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		239.6	245.1
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure		493.4	493.7
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]	8.1	0.3
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]	245.7	248.3
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		61.3	58.3
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]	61.3	58.3
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 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.