Risk Management and Fair Values (Assets And Liabilities At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	$ 1,675,082	$ 1,630,248
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	44,000	42,000
Replacement Reserve Escrow	103,000	148,000
Equity Securities, FV-NI	807,000	1,533,000
Debt Securities	3,436,000	2,617,000
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	9,172,000	9,122,000
Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis	3,000	7,000
Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Available-for-sale Securities	3,102,000	3,103,000
Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset		38,000
Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,000	2,000
Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	4,000	9,000
Fair Value Inputs Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	1,675,000	1,630,000
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	44,000	42,000
Replacement Reserve Escrow	103,000	148,000
Equity Securities, FV-NI	807,000	1,533,000
Debt Securities	1,489,000	919,000
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	4,119,000	4,273,000
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	2,000	6,000
Fair Value Inputs Level 1 [Member] | Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset		0
Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,000	1,000
Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Replacement Reserve Escrow	0	0
Equity Securities, FV-NI	0	0
Debt Securities	1,947,000	1,698,000
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	1,947,000	1,699,000
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	1,000	1,000
Fair Value, Inputs, Level 2 [Member] | Power Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset		0
Fair Value, Inputs, Level 2 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	1,000
Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Replacement Reserve Escrow	0	0
Equity Securities, FV-NI	0	0
Debt Securities	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	4,000	47,000
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 Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset		38,000
Fair Value, Inputs, Level 3 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	4,000	9,000
Entergy New Orleans [Member]
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	6,779	3,364
Replacement Reserve Escrow	38,800	83,000
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	45,700	86,500
Entergy New Orleans [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis		300
Entergy New Orleans [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	100	100
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member]
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	6,800	3,400
Replacement Reserve Escrow	38,800	83,000
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	45,600	86,400
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		300
Entergy New Orleans [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy New Orleans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Replacement Reserve Escrow	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	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
Entergy New Orleans [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy New Orleans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Replacement Reserve Escrow	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	100	100
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
Entergy New Orleans [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	100	100
Entergy Mississippi [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	76,705	7
Assets at fair value on a recurring basis
Replacement Reserve Escrow	64,600	64,600
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	141,600	65,200
Entergy Mississippi [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis	2,300	5,000
Entergy Mississippi [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	300	600
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	76,700
Assets at fair value on a recurring basis
Replacement Reserve Escrow	64,600	64,600
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	141,300	64,600
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	2,300	5,000
Entergy Mississippi [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Mississippi [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0
Assets at fair value on a recurring basis
Replacement Reserve Escrow	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	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] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Mississippi [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0
Assets at fair value on a recurring basis
Replacement Reserve Escrow	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	300	600
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] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	300	600
Entergy Louisiana [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	601,583	726,717
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	8,800	2,700
Equity Securities, FV-NI	68,800	8,700
Debt Securities	632,800	632,200
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	2,492,300	2,528,900
Entergy Louisiana [Member] | Gas Hedge Contracts [Member]
Liabilities at fair value on a recurring basis
Liabilities, Fair Value Disclosure on Recurring Basis	800	1,600
Entergy Louisiana [Member] | Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Available-for-sale Securities	1,177,700	1,153,100
Entergy Louisiana [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,400	1,300
Entergy Louisiana [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,200	4,200
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	601,600	726,700
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	8,800	2,700
Equity Securities, FV-NI	68,800	8,700
Debt Securities	218,900	172,400
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	899,100	911,300
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	0	300
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,000	800
Entergy Louisiana [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Equity Securities, FV-NI	0	0
Debt Securities	413,900	459,800
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	414,300	460,300
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	800	1,300
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	400	500
Entergy Louisiana [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Equity Securities, FV-NI	0	0
Debt Securities	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	1,200	4,200
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] | Gas Hedge Contracts Assets [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Louisiana [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,200	4,200
Entergy Arkansas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	123,658	168,020
Assets at fair value on a recurring basis
Equity Securities, FV-NI	53,300	1,300
Debt Securities	425,900	447,900
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	1,436,200	1,444,600
Entergy Arkansas [Member] | Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Available-for-sale Securities	831,900	824,700
Entergy Arkansas [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,400	2,700
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	123,700	168,000
Assets at fair value on a recurring basis
Equity Securities, FV-NI	53,300	1,300
Debt Securities	89,900	98,200
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	266,900	267,500
Entergy Arkansas [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Equity Securities, FV-NI	0	0
Debt Securities	336,000	349,700
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	336,000	349,700
Entergy Arkansas [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Equity Securities, FV-NI	0	0
Debt Securities	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	1,400	2,700
Entergy Arkansas [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	1,400	2,700
Entergy Texas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	248,570
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	28,072	36,233
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	28,600	286,400
Entergy Texas [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	500	1,600
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value		248,600
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	28,100	36,200
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	28,100	284,800
Entergy Texas [Member] | Fair Value Inputs Level 1 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Texas [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value		0
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	0	0
Entergy Texas [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	0	0
Entergy Texas [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value		0
Assets at fair value on a recurring basis
Restricted Cash and Cash Equivalents, Current	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	500	1,600
Entergy Texas [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Transmission Rights (FTRs) [Member]
Assets at fair value on a recurring basis
Derivative Asset	500	1,600
System Energy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	132,149	216,383
Assets at fair value on a recurring basis
Equity Securities, FV-NI	60,600	3,800
Debt Securities	406,400	427,700
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	1,381,900	1,432,300
System Energy [Member] | Common trust funds valued using Net Asset Value [Domain]
Assets at fair value on a recurring basis
Available-for-sale Securities	782,800	784,400
System Energy [Member] | Fair Value Inputs Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	132,100	216,400
Assets at fair value on a recurring basis
Equity Securities, FV-NI	60,600	3,800
Debt Securities	179,400	177,300
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	372,100	397,500
System Energy [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Equity Securities, FV-NI	0	0
Debt Securities	227,000	250,400
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	227,000	250,400
System Energy [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	0	0
Assets at fair value on a recurring basis
Equity Securities, FV-NI	0	0
Debt Securities	0	0
Liabilities at fair value on a recurring basis
Assets, Fair Value Disclosure	$ 0	$ 0