Summary Of Significant Accounting Policies (Schedule Of Subsidiaries' Investment And Accumulated Depreciation In Generating Stations) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012 MW
Independence Unit 1 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	836	[1]
Ownership	31.50%
Investment	$ 128
Accumulated Depreciation	86
Independence Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Ownership	15.75%
Investment	33
Accumulated Depreciation	22
Independence Common Facilities [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Ownership	7.18%
Investment	16
Accumulated Depreciation	9
White Bluff Units 1 And 2 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	1,659	[1]
Ownership	57.00%
Investment	498
Accumulated Depreciation	319
Ouachita Common Facilities [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Gas	[2]
Ownership	66.67%	[2]
Investment	169	[2]
Accumulated Depreciation	142	[2]
Ouachita Common Facilities [Member] | Entergy Gulf States Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Gas	[2]
Ownership	33.33%	[2]
Investment	87	[2]
Accumulated Depreciation	73	[2]
Roy S. Nelson Unit 6 [Member] | Entergy Gulf States Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	540	[1]
Ownership	40.25%
Investment	250
Accumulated Depreciation	170
Roy S. Nelson Unit 6 [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	540	[1]
Ownership	29.75%
Investment	180
Accumulated Depreciation	113
Roy S. Nelson Unit 6 [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	540	[1]
Ownership	10.90%
Investment	104
Accumulated Depreciation	54
Roy S. Nelson Unit 6 Common Facilities [Member] | Entergy Gulf States Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Ownership	15.92%
Investment	9
Accumulated Depreciation	3
Roy S. Nelson Unit 6 Common Facilities [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Ownership	11.77%
Investment	6
Accumulated Depreciation	2
Roy S. Nelson Unit 6 Common Facilities [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Ownership	4.31%
Investment	2
Accumulated Depreciation	1
Big Cajun 2 Unit 3 [Member] | Entergy Gulf States Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	588	[1]
Ownership	24.15%
Investment	142
Accumulated Depreciation	99
Big Cajun 2 Unit 3 [Member] | Entergy Texas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	588	[1]
Ownership	17.85%
Investment	107
Accumulated Depreciation	68
Acadia Common Facilities [Member] | Entergy Louisiana [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Gas
Ownership	50.00%
Investment	8
Independence Units 1 And 2 And Common Facilities [Member] | Entergy Mississippi [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	1,678	[1]
Ownership	25.00%
Investment	250
Accumulated Depreciation	140
Grand Gulf Unit 1 [Member] | System Energy [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Nuclear
Total Megawatt Capability	1,430	[1]
Ownership	90.00%
Investment	4,557
Accumulated Depreciation	2,569
Independence Unit 2 [Member] | Entergy Wholesale Commodities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Fuel-Type	Coal
Total Megawatt Capability	842	[1]
Ownership	14.37%
Investment	69
Accumulated Depreciation	$ 43
Ouachita Units 1 and 2 [Member] | Entergy Arkansas [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership	100.00%
Ouachita Unit 3 [Member] | Entergy Gulf States 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 Gulf States Louisiana. The investment and accumulated depreciation numbers above are only for the common facilities and not for the generating units.