Summary Of Significant Accounting Policies (Schedule Of Subsidiaries' Investment And Accumulated Depreciation In Generating Stations) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) MW
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	836
Ownership	31.50%
Investment	$ 140
Accumulated Depreciation	$ 103
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	$ 34
Accumulated Depreciation	$ 27
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	$ 17
Accumulated Depreciation	$ 12
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	1,636
Ownership	57.00%
Investment	$ 531
Accumulated Depreciation	$ 364
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	$ 172
Accumulated Depreciation	$ 150
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	$ 75
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	550
Ownership	40.25%
Investment	$ 280
Accumulated Depreciation	$ 194
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	550
Ownership	29.75%
Investment	$ 200
Accumulated Depreciation	$ 114
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	550
Ownership	10.90%
Investment	$ 113
Accumulated Depreciation	$ 62
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	25.79%
Investment	$ 15
Accumulated Depreciation	$ 6
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	14.16%
Investment	$ 6
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	5.19%
Investment	$ 2
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	574
Ownership	24.15%
Investment	$ 150
Accumulated Depreciation	$ 117
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	574
Ownership	17.85%
Investment	$ 113
Accumulated Depreciation	$ 76
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	$ 2
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	$ 3
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	$ 20
Accumulated Depreciation	$ 0
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	1,678
Ownership	25.00%
Investment	$ 266
Accumulated Depreciation	$ 156
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	1,414
Ownership	90.00%
Investment	$ 4,916
Accumulated Depreciation	$ 3,175
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	$ 73
Accumulated Depreciation	$ 50
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 Units 1 and 2 Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	50.00%
Investment	$ 1
Accumulated Depreciation	$ 0
Union Units 1 and 2 Common Facilities [Member] | Entergy New Orleans [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas
Ownership	50.00%
Investment	$ 1
Accumulated Depreciation	$ 0
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	$ 28
Accumulated Depreciation	$ 3
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	$ 55
Accumulated Depreciation	$ 3
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	$ 28
Accumulated Depreciation	$ 3
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%