Decommissioning Trust Funds (Fair Value Of Debt Securities By Contractual Maturities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair value of debt securities by contractual maturities
Less than 1 year	$ 95.0	$ 83.0
1 year - 5 years	787.0	752.0
5 years - 10 years	637.0	620.0
10 years - 15 years	168.0	169.0
15 years - 20 years	51.0	52.0
20 years+	192.0	154.0
Total	1,930.0	1,830.0
Entergy Arkansas [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	8.1	8.1
1 year - 5 years	125.5	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+	6.4	5.8
Total	260.7	247.6
Entergy Gulf States Louisiana [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	7.8	7.9
1 year - 5 years	52.7	51.2
5 years - 10 years	91.2	75.5
10 years - 15 years	59.6	55.8
15 years - 20 years	4.6	4.6
20 years+	10.4	7.9
Total	226.3	202.9
Entergy Louisiana [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	8.7	14.8
1 year - 5 years	44.9	41.9
5 years - 10 years	44.4	37.0
10 years - 15 years	6.5	6.6
15 years - 20 years	6.7	6.2
20 years+	17.4	16.6
Total	128.6	123.1
System Energy [Member]
Fair value of debt securities by contractual maturities
Less than 1 year	8.8	5.5
1 year - 5 years	157.8	144.9
5 years - 10 years	39.8	44.3
10 years - 15 years	3.5	9.3
15 years - 20 years	1.3	1.6
20 years+	22.2	18.3
Total	$ 233.4	$ 223.9