Decommissioning Trust Funds (Schedule of Realized Gain (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Proceeds from Sale of Debt Securities, Available-for-sale	$ 1,258.0	$ 661.0	$ 889.0
Debt Securities, Available-for-Sale, Realized Gain	5.0	1.0	2.0
Debt Securities, Available-for-Sale, Realized Loss	89.0	37.0	46.0
Entergy Arkansas [Member]
Proceeds from Sale of Debt Securities, Available-for-sale	210.6	28.5	42.1
Debt Securities, Available-for-Sale, Realized Gain	0.1	0.1	0.1
Debt Securities, Available-for-Sale, Realized Loss	35.8	2.0	2.6
Entergy Louisiana [Member]
Proceeds from Sale of Debt Securities, Available-for-sale	547.8	318.6	362.2
Debt Securities, Available-for-Sale, Realized Gain	1.3	0.5	1.3
Debt Securities, Available-for-Sale, Realized Loss	25.8	20.9	23.0
System Energy [Member]
Proceeds from Sale of Debt Securities, Available-for-sale	500.1	314.3	209.4
Debt Securities, Available-for-Sale, Realized Gain	3.1	0.6	0.2
Debt Securities, Available-for-Sale, Realized Loss	$ 28.0	$ 14.2	$ 10.7