Summary Of Significant Accounting Policies (Schedule Of Subsidiaries' Investment And Accumulated Depreciation In Generating Stations) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) MW
System Energy [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	90.00%
Independence Unit 1 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	822
Ownership	31.50%
Investment	$ 142
Accumulated Depreciation	$ 105
Independence Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	15.75%
Investment	$ 43
Accumulated Depreciation	$ 30
Independence Common Facilities [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	7.18%
Investment	$ 20
Accumulated Depreciation	$ 14
White Bluff Units 1 And 2 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	1,640
Ownership	57.00%
Investment	$ 585
Accumulated Depreciation	$ 383
Ouachita Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	66.67%
Investment	$ 173
Accumulated Depreciation	$ 154
Ouachita Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	33.33%
Investment	$ 90
Accumulated Depreciation	$ 77
Roy S. Nelson Unit 6 [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	524
Ownership	40.25%
Investment	$ 291
Accumulated Depreciation	$ 209
Roy S. Nelson Unit 6 [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	524
Ownership	29.75%
Investment	$ 206
Accumulated Depreciation	$ 119
Roy S. Nelson Unit 6 [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	524
Ownership	10.90%
Investment	$ 117
Accumulated Depreciation	$ 67
Roy S. Nelson Unit 6 Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	20.98%
Investment	$ 21
Accumulated Depreciation	$ 9
Roy S. Nelson Unit 6 Common Facilities [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	15.52%
Investment	$ 7
Accumulated Depreciation	$ 3
Roy S. Nelson Unit 6 Common Facilities [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	5.68%
Investment	$ 3
Accumulated Depreciation	$ 1
Big Cajun 2 Unit 3 [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	558
Ownership	24.15%
Investment	$ 151
Accumulated Depreciation	$ 128
Big Cajun 2 Unit 3 [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	558
Ownership	17.85%
Investment	$ 113
Accumulated Depreciation	$ 82
Big Cajun 2 Unit 3 Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	8.05%
Investment	$ 5
Accumulated Depreciation	$ 3
Big Cajun 2 Unit 3 Common Facilities [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Ownership	5.95%
Investment	$ 4
Accumulated Depreciation	$ 1
Acadia Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	50.00%
Investment	$ 21
Accumulated Depreciation	$ 1
Independence Units 1 And 2 And Common Facilities [Member] | Entergy Mississippi [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	1,664
Ownership	25.00%
Investment	$ 284
Accumulated Depreciation	$ 173
Grand Gulf Unit 1 [Member] | System Energy [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Nuclear
Total Megawatt Capability | MW	1,396
Ownership	90.00%
Investment	$ 5,310
Accumulated Depreciation	$ 3,280
Independence Unit 2 [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Coal
Total Megawatt Capability | MW	842
Ownership	14.37%
Investment	$ 74
Accumulated Depreciation	$ 55
Ouachita Units 1 and 2 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	100.00%
Ouachita Unit 3 [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	100.00%
Union Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	25.00%
Investment	$ 29
Accumulated Depreciation	$ 7
Union Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	50.00%
Investment	$ 59
Accumulated Depreciation	$ 8
Union Common Facilities [Member] | Entergy New Orleans [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	25.00%
Investment	$ 29
Accumulated Depreciation	$ 7
Union Unit 1 [Member] | Entergy New Orleans [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	100.00%
Union Unit 2 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	100.00%
Union Units 3 and 4 [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	100.00%