Summary Of Significant Accounting Policies (Schedule Of Subsidiaries' Investment And Accumulated Depreciation In Generating Stations) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 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	839	[1]
Ownership	31.50%
Investment	$ 134
Accumulated Depreciation	$ 100
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	$ 33
Accumulated Depreciation	$ 26
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	$ 16
Accumulated Depreciation	$ 11
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	1,637	[1]
Ownership	57.00%
Investment	$ 520
Accumulated Depreciation	$ 361
Ouachita Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas	[2]
Total Megawatt Capability | MW	489	[2]
Ownership	66.67%	[2]
Investment	$ 170	[2]
Accumulated Depreciation	$ 147	[2]
Ouachita Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas	[2]
Total Megawatt Capability | MW	243	[2]
Ownership	33.33%	[2]
Investment	$ 87	[2]
Accumulated Depreciation	$ 74	[2]
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	537	[1]
Ownership	40.25%
Investment	$ 274
Accumulated Depreciation	$ 185
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	537	[1]
Ownership	29.75%
Investment	$ 197
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	537	[1]
Ownership	10.90%
Investment	$ 111
Accumulated Depreciation	$ 58
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	17.26%
Investment	$ 11
Accumulated Depreciation	$ 5
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	12.75%
Investment	$ 6
Accumulated Depreciation	$ 2
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	4.67%
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	594	[1]
Ownership	24.15%
Investment	$ 151
Accumulated Depreciation	$ 109
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	594	[1]
Ownership	17.85%
Investment	$ 113
Accumulated Depreciation	$ 73
Acadia Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Fuel Type	Gas	[2]
Total Megawatt Capability | MW	551	[2]
Ownership	50.00%	[2]
Investment	$ 19	[2]
Accumulated Depreciation	$ 0	[2]
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	1,681	[1]
Ownership	25.00%
Investment	$ 258
Accumulated Depreciation	$ 152
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	1,409	[1]
Ownership	90.00%	[3]
Investment	$ 4,829
Accumulated Depreciation	$ 2,962
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	[1]
Ownership	14.37%
Investment	$ 71
Accumulated Depreciation	$ 47
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%

[1] “Total Megawatt Capability” is the dependable load carrying capability as demonstrated under actual operating conditions based on the primary fuel (assuming no curtailments) that each station was designed to utilize.

[2] Ouachita Units 1 and 2 are owned 100% by Entergy Arkansas and Ouachita Unit 3 is owned 100% by Entergy Louisiana. The investment and accumulated depreciation numbers above are only for the common facilities and not for the generating units.

[3] Includes a leasehold interest held by System Energy. System Energy’s Grand Gulf lease obligations are discussed in Note 10 to the financial statements.