Decommissioning Trust Funds (Securities Held) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 4,903.0	$ 4,190.0
Total Unrealized Gains	1,307.0	778.0
Total Unrealized Losses	29.0	6.0
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	3,073.0	2,459.0
Total Unrealized Gains	1,260.0	662.0
Total Unrealized Losses	0	1.0
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,830.0	1,731.0
Total Unrealized Gains	47.0	116.0
Total Unrealized Losses	29.0	5.0
Entergy Arkansas [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	710.9	600.6
Total Unrealized Gains	219.3	130.6
Total Unrealized Losses	5.2	0.2
Entergy Arkansas [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	463.3	384.0
Total Unrealized Gains	214.0	116.1
Total Unrealized Losses	0	0
Entergy Arkansas [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	247.6	216.6
Total Unrealized Gains	5.3	14.5
Total Unrealized Losses	5.2	0.2
Entergy Gulf States Louisiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	573.7	477.4
Total Unrealized Gains	149.2	85.6
Total Unrealized Losses	3.5	0.1
Entergy Gulf States Louisiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	370.8	288.5
Total Unrealized Gains	141.8	69.8
Total Unrealized Losses	0	0
Entergy Gulf States Louisiana [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	202.9	188.9
Total Unrealized Gains	7.4	15.8
Total Unrealized Losses	3.5	0.1
Entergy Louisiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	347.3	287.4
Total Unrealized Gains	100.8	58.3
Total Unrealized Losses	1.9	0.2
Entergy Louisiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	224.2	175.5
Total Unrealized Gains	96.1	48.9
Total Unrealized Losses	0	0.1
Entergy Louisiana [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	123.1	111.9
Total Unrealized Gains	4.7	9.4
Total Unrealized Losses	1.9	0.1
System Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	603.9	490.6
Total Unrealized Gains	154.3	72.9
Total Unrealized Losses	1.8	0.3
System Energy [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	380.0	283.6
Total Unrealized Gains	150.8	63.6
Total Unrealized Losses	0	0.2
System Energy [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	223.9	207.0
Total Unrealized Gains	3.5	9.3
Total Unrealized Losses	$ 1.8	$ 0.1