Decommissioning Trust Funds (Schedule of Realized Gain (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Proceeds from Sale of Debt Securities, Available-for-sale	$ 902.0	$ 1,258.0	$ 661.0
Debt Securities, Available-for-Sale, Realized Gain	6.0	5.0	1.0
Debt Securities, Available-for-Sale, Realized Loss	13.0	89.0	37.0
Entergy Arkansas [Member]
Proceeds from Sale of Debt Securities, Available-for-sale	41.7	210.6	28.5
Debt Securities, Available-for-Sale, Realized Gain	0.5	0.1	0.1
Debt Securities, Available-for-Sale, Realized Loss	0.1	35.8	2.0
Entergy Louisiana [Member]
Proceeds from Sale of Debt Securities, Available-for-sale	398.8	547.8	318.6
Debt Securities, Available-for-Sale, Realized Gain	2.2	1.3	0.5
Debt Securities, Available-for-Sale, Realized Loss	7.0	25.8	20.9
System Energy [Member]
Proceeds from Sale of Debt Securities, Available-for-sale	461.8	500.1	314.3
Debt Securities, Available-for-Sale, Realized Gain	3.4	3.1	0.6
Debt Securities, Available-for-Sale, Realized Loss	$ 5.8	$ 28.0	$ 14.2