Decommissioning Trust Funds (Fair Value Of Debt Securities By Contractual Maturities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair value of debt securities by contractual maturities
Less than 1 year	$ 91.0	$ 83.0
1 year - 5 years	812.0	752.0
5 years - 10 years	612.0	620.0
10 years - 15 years	169.0	169.0
15 years - 20 years	60.0	52.0
20 years+	228.0	154.0
Total	1,972.0	1,830.0
Entergy Arkansas [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	5.6	8.1
1 year - 5 years	131.1	110.9
5 years - 10 years	116.4	118.0
10 years - 15 years	3.3	3.9
15 years - 20 years	1.0	0.9
20 years+	7.8	5.8
Total	265.2	247.6
Entergy Gulf States Louisiana [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	5.9	7.9
1 year - 5 years	53.2	51.2
5 years - 10 years	83.6	75.5
10 years - 15 years	55.8	55.8
15 years - 20 years	6.0	4.6
20 years+	24.4	7.9
Total	228.9	202.9
Entergy Louisiana [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	7.8	14.8
1 year - 5 years	54.4	41.9
5 years - 10 years	42.5	37.0
10 years - 15 years	6.7	6.6
15 years - 20 years	7.8	6.2
20 years+	17.4	16.6
Total	136.6	123.1
System Energy [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	17.7	5.5
1 year - 5 years	152.3	144.9
5 years - 10 years	44.7	44.3
10 years - 15 years	1.3	9.3
15 years - 20 years	3.5	1.6
20 years+	22.1	18.3
Total	$ 241.6	$ 223.9