Revolving Credit Facilities, Lines Of Credit And Short-Term Borrowings (Book Value And The Fair Value Of Long-Term Debt) (Details) (USD $)	Jun. 30, 2012		Mar. 31, 2012
Short-term Debt [Line Items]
Long-term Debt, Fair Value			$ 12,617,931,000	[1],[2]
Long-term Debt, Book Value			12,389,324,000
Notes payable to power authority	135,000,000
Entergy Arkansas [Member]
Short-term Debt [Line Items]
Long-term Debt, Fair Value	1,763,739,000	[1],[2]
Long-term Debt, Book Value	1,870,015,000
Long term DOE obligations	181,000,000
Entergy Gulf States Louisiana [Member]
Short-term Debt [Line Items]
Long-term Debt, Fair Value	1,636,552,000	[1],[2]
Long-term Debt, Book Value	1,505,810,000
Entergy Louisiana [Member]
Short-term Debt [Line Items]
Long-term Debt, Fair Value	2,498,456,000	[1],[2]
Long-term Debt, Book Value	2,420,377,000
Capital Lease Obligations	169,000,000
Entergy Mississippi [Member]
Short-term Debt [Line Items]
Long-term Debt, Fair Value	1,004,657,000	[1],[2]
Long-term Debt, Book Value	920,469,000
Entergy New Orleans
Short-term Debt [Line Items]
Long-term Debt, Fair Value	172,351,000	[1],[2]
Long-term Debt, Book Value	166,319,000
Entergy Texas [Member]
Short-term Debt [Line Items]
Long-term Debt, Fair Value	1,888,272,000	[1],[2]
Long-term Debt, Book Value	1,645,057,000
System Energy [Member]
Short-term Debt [Line Items]
Long-term Debt, Fair Value	631,169,000	[1],[2]
Long-term Debt, Book Value	757,194,000
Capital Lease Obligations	$ 139,000,000

[1] The values exclude lease obligations of $169 million at Entergy Louisiana and $139 million at System Energy, long-term DOE obligations of $181 million at Entergy Arkansas, and the note payable to NYPA of $135 million at Entergy, and include debt due within one year.

[2] Fair values are classified as Level 2 in the fair value hierarchy discussed in Note 8 to the financial statements and are based on prices derived from inputs such as benchmark yields and reported trades.