Decommissioning Trust Funds (Securities Held) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 5,165.0	$ 4,903.0
Total Unrealized Gains	1,476.0	1,307.0
Total Unrealized Losses	9.0	29.0
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	3,193.0	3,073.0
Total Unrealized Gains	1,409.0	1,260.0
Total Unrealized Losses	1.0	0
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,972.0	1,830.0
Total Unrealized Gains	67.0	47.0
Total Unrealized Losses	8.0	29.0
Entergy Arkansas [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	746.2	710.9
Total Unrealized Gains	244.9	219.3
Total Unrealized Losses	1.5	5.2
Entergy Arkansas [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	481.0	463.3
Total Unrealized Gains	238.4	214.0
Total Unrealized Losses	0	0
Entergy Arkansas [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	265.2	247.6
Total Unrealized Gains	6.5	5.3
Total Unrealized Losses	1.5	5.2
Entergy Gulf States Louisiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	607.6	573.7
Total Unrealized Gains	171.8	149.2
Total Unrealized Losses	0.9	3.5
Entergy Gulf States Louisiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	378.7	370.8
Total Unrealized Gains	161.1	141.8
Total Unrealized Losses	0	0
Entergy Gulf States Louisiana [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	228.9	202.9
Total Unrealized Gains	10.7	7.4
Total Unrealized Losses	0.9	3.5
Entergy Louisiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	366.6	347.3
Total Unrealized Gains	113.5	100.8
Total Unrealized Losses	0.7	1.9
Entergy Louisiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	230.0	224.2
Total Unrealized Gains	107.5	96.1
Total Unrealized Losses	0	0
Entergy Louisiana [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	136.6	123.1
Total Unrealized Gains	6.0	4.7
Total Unrealized Losses	0.7	1.9
System Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	645.2	603.9
Total Unrealized Gains	176.4	154.3
Total Unrealized Losses	0.3	1.8
System Energy [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	403.6	380.0
Total Unrealized Gains	171.4	150.8
Total Unrealized Losses	0	0
System Energy [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	241.6	223.9
Total Unrealized Gains	5.0	3.5
Total Unrealized Losses	$ 0.3	$ 1.8