Summary Of Significant Accounting Policies (Narrative) (Details) $ in Thousands	1 Months Ended			3 Months Ended		12 Months Ended
	Mar. 31, 2019 $ / kWh	Mar. 31, 2018 $ / kWh	Mar. 31, 2017 $ / kWh	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 USD ($) $ / kWh shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares	Jan. 31, 2019 USD ($)
Operating and Finance Lease Right of Use Asset and Lease Liabilities at Implementation									$ 263,000
Income Tax Expense (Benefit)						$ (121,506)	$ (169,825)	$ (1,036,826)
Depreciation rates on average depreciable property						2.80%	2.80%	2.80%
Depreciation rates on average depreciable utility property						2.70%	2.60%	2.60%
Depreciation rates on average depreciable non-utility property						12.70%	18.30%	18.60%
Accumulated depreciation of non-utility property						$ 191,000	$ 184,000
Construction expenditures in accounts payable						$ 745,000	$ 406,000
Options outstanding excluded from the calculation of diluted earnings per share | shares						523,999	173,290	956,550
Incremental Common Shares Attributable to Share-based Payment Arrangements | shares						500,000	600,000	300,000
Asset Retirement Obligations, Noncurrent						$ 6,469,452	$ 6,159,212
Asset Impairment Charges						26,623	290,027	$ 532,321
After-Tax Asset Impairment Charge				$ 4,200
Asset Write-Offs, Impairments, And Related Charges						26,379	226,678	491,739
Assets, Fair Value Disclosure						9,122,000	7,430,000
Property, Plant and Equipment, Net						343,328	332,864
Decommissioning						381,861	400,802	388,508
Entergy Wholesale Commodities [Member]
Income Tax Expense (Benefit)						104,937	(161,295)	(269,025)
Asset Write-Offs, Impairments, And Related Charges						19,000	290,000	532,000
Impairment of Long-Lived Assets Held-For-Use, Net of Tax							79,000
Asset Write-Offs, Impairments, And Related Charges						26,623	290,027	532,321
Entergy Louisiana [Member]
Operating and Finance Lease Right of Use Asset and Lease Liabilities at Implementation									51,000
Income Tax Expense (Benefit)						$ (382,324)	$ 121,623	$ (54,611)
Depreciation rates on average depreciable property						2.40%	2.40%	2.30%
Accumulated depreciation of non-utility property						$ 179,800	$ 168,500
Construction expenditures in accounts payable						$ 460,500	115,100
Percentage Interest in River Bend						30.00%
Portion of percentage of interest of River Bend plant costs, generation, revenues and expenses operating the Louisiana retail deregulated portion of River Bend						15.00%
Rate At Which Electricity Sold To Retail Customers | $ / kWh						0.046
Limit above which incremental revenue shared between ratepayers and shareholders | $ / kWh						0.046
Asset Retirement Obligations, Noncurrent						$ 1,573,307	1,497,349
Assets, Fair Value Disclosure						2,528,900	1,870,200
Property, Plant and Equipment, Net						323,110	312,896
Decommissioning						65,225	59,346	$ 53,736
Entergy Texas [Member]
Operating and Finance Lease Right of Use Asset and Lease Liabilities at Implementation									16,000
Income Tax Expense (Benefit)						$ 3,042	$ (53,896)	$ (26,243)
Depreciation rates on average depreciable property						3.10%	3.00%	2.70%
Accumulated depreciation of non-utility property							$ 4,900
Construction expenditures in accounts payable						$ 116,800	88,100
Asset Retirement Obligations, Noncurrent						8,063	7,631
Assets, Fair Value Disclosure						286,400	51,500
Property, Plant and Equipment, Net						376	376
Entergy Arkansas [Member]
Operating and Finance Lease Right of Use Asset and Lease Liabilities at Implementation									59,000
Income Tax Expense (Benefit)						$ 47,777	$ (46,769)	$ (297,067)
Depreciation rates on average depreciable property						2.60%	2.50%	2.50%
Construction expenditures in accounts payable						$ 59,700	$ 67,900
Rate At Which Electricity Sold To Retail Customers | $ / kWh	0.01882	0.01547	0.01164
Asset Retirement Obligations, Noncurrent						1,314,160	1,242,616
Assets, Fair Value Disclosure						1,444,600	1,108,600
Decommissioning						73,319	68,030	$ 60,420
Entergy Mississippi [Member]
Operating and Finance Lease Right of Use Asset and Lease Liabilities at Implementation									26,000
Income Tax Expense (Benefit)						$ 27,190	$ 30,866	$ (125,773)
Depreciation rates on average depreciable property						3.50%	3.20%	3.20%
Accumulated depreciation of non-utility property						$ 500	$ 500
Construction expenditures in accounts payable						31,400	34,200
Asset Retirement Obligations, Noncurrent						9,762	9,727
Assets, Fair Value Disclosure						65,200	132,600
Property, Plant and Equipment, Net						4,543	4,560
Entergy New Orleans [Member]
Operating and Finance Lease Right of Use Asset and Lease Liabilities at Implementation									$ 7,000
Income Tax Expense (Benefit)						$ (4,207)	$ 186	$ (2,436)
Depreciation rates on average depreciable property						3.10%	3.20%	3.50%
Construction expenditures in accounts payable						$ 9,200	$ 18,400
Asset Retirement Obligations, Noncurrent						3,768	3,522
Assets, Fair Value Disclosure						86,500	90,900
Property, Plant and Equipment, Net						1,016	1,016
System Energy [Member]
Income Tax Expense (Benefit)						$ 20,543	$ 15,349	$ (47,675)
Depreciation rates on average depreciable property						2.10%	2.10%	1.90%
Construction expenditures in accounts payable						$ 17,700	$ 23,200
Asset Retirement Obligations, Noncurrent						968,910	931,729
Assets, Fair Value Disclosure						1,432,300	1,122,500
Decommissioning						$ 37,181	$ 35,729	$ 34,336
Vermont Yankee [Member] | Entergy Wholesale Commodities [Member]
Asset Impairment Charges					$ 173,000