Decommissioning Trust Funds (Available For Sale Securities Continuous Unrealized Loss Position Fair Value) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	$ 13,000,000	$ 9,000,000
More than 12 months Fair Value	0	0
Total Fair Value	13,000,000	9,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,000,000	1,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,000,000	1,000,000
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	213,000,000	277,000,000
More than 12 months Fair Value	80,000,000	163,000,000
Total Fair Value	293,000,000	440,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2,000,000	2,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,000,000	4,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	4,000,000	6,000,000
Entergy Arkansas [Member] \| Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	1,000,000	100,000
More than 12 months Fair Value	0	0
Total Fair Value	1,000,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Entergy Arkansas [Member] \| Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	29,600,000	56,500,000
More than 12 months Fair Value	19,600,000	34,800,000
Total Fair Value	49,200,000	91,300,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	300,000	300,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	300,000	800,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	600,000	1,100,000
Entergy Gulf States Louisiana [Member] \| Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	1,700,000	100,000
More than 12 months Fair Value	0	0
Total Fair Value	1,700,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Entergy Gulf States Louisiana [Member] \| Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	18,100,000	14,000,000
More than 12 months Fair Value	2,100,000	15,000,000
Total Fair Value	20,200,000	29,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	200,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	200,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	200,000	300,000
Entergy Louisiana [Member] \| Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	600,000	100,000
More than 12 months Fair Value	0	0
Total Fair Value	600,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
Entergy Louisiana [Member] \| Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	10,500,000	19,100,000
More than 12 months Fair Value	4,200,000	12,100,000
Total Fair Value	14,700,000	31,200,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	100,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	100,000	300,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	200,000	400,000
System Energy [Member] \| Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	1,000,000	100,000
More than 12 months Fair Value	0	0
Total Fair Value	1,000,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0
System Energy [Member] \| Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	20,500,000	51,600,000
More than 12 months Fair Value	2,600,000	6,500,000
Total Fair Value	23,100,000	58,100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	200,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	100,000	100,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 100,000	$ 300,000

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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