Decommissioning Trust Funds (Available For Sale Securities Continuous Unrealized Loss Position Fair Value) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Gross Unrealized Losses	$ 0
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	0	37.0
More than 12 months Fair Value	0	20.0
Total Fair Value	0	57.0
Less than 12 months Gross Unrealized Losses	0	1.0
More than 12 months Gross Unrealized Losses	0	0
Total Gross Unrealized Losses	0	1.0
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	892.0	175.0
More than 12 months Fair Value	60.0	48.0
Total Fair Value	952.0	223.0
Less than 12 months Gross Unrealized Losses	24.0	1.0
More than 12 months Gross Unrealized Losses	5.0	4.0
Total Gross Unrealized Losses	29.0	5.0
Entergy Arkansas [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	0	0.2
More than 12 months Fair Value	0	0
Total Fair Value	0	0.2
Less than 12 months Gross Unrealized Losses	0	0
More than 12 months Gross Unrealized Losses	0	0
Total Gross Unrealized Losses	0	0
Entergy Arkansas [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	153.2	24.4
More than 12 months Fair Value	6.9	1.0
Total Fair Value	160.1	25.4
Less than 12 months Gross Unrealized Losses	4.8	0.2
More than 12 months Gross Unrealized Losses	0.4	0
Total Gross Unrealized Losses	5.2	0.2
Entergy Gulf States Louisiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	0	1.2
More than 12 months Fair Value	0	1.0
Total Fair Value	0	2.2
Less than 12 months Gross Unrealized Losses	0	0
More than 12 months Gross Unrealized Losses	0	0
Total Gross Unrealized Losses	0	0
Entergy Gulf States Louisiana [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	91.9	9.1
More than 12 months Fair Value	4.6	0
Total Fair Value	96.5	9.1
Less than 12 months Gross Unrealized Losses	3.1	0.1
More than 12 months Gross Unrealized Losses	0.4	0
Total Gross Unrealized Losses	3.5	0.1
Entergy Louisiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	0	0.7
More than 12 months Fair Value	0	5.6
Total Fair Value	0	6.3
Less than 12 months Gross Unrealized Losses	0	0
More than 12 months Gross Unrealized Losses	0	0.1
Total Gross Unrealized Losses	0	0.1
Entergy Louisiana [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	38.3	3.4
More than 12 months Fair Value	1.7	0.5
Total Fair Value	40.0	3.9
Less than 12 months Gross Unrealized Losses	1.7	0
More than 12 months Gross Unrealized Losses	0.2	0.1
Total Gross Unrealized Losses	1.9	0.1
System Energy [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	0	1.4
More than 12 months Fair Value	0	13.0
Total Fair Value	0	14.4
Less than 12 months Gross Unrealized Losses		0
More than 12 months Gross Unrealized Losses	0	0.2
Total Gross Unrealized Losses	0	0.2
System Energy [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	121.7	15.5
More than 12 months Fair Value	0.9	0
Total Fair Value	122.6	15.5
Less than 12 months Gross Unrealized Losses	1.7	0.1
More than 12 months Gross Unrealized Losses	0.1	0
Total Gross Unrealized Losses	$ 1.8	$ 0.1