Decommissioning Trust Funds (Debt Securities, Available-for-Sale) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	$ 2,047.0	$ 1,770.0
Debt Securities, Available-for-Sale, Unrealized Gain	7.0	19.0
Debt Securities, Available-for-Sale, Unrealized Loss	80.0	134.0
Debt Securities, Available-for-Sale, Unrealized Loss Position	80.0	134.0
Entergy Louisiana [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	908.1	788.1
Debt Securities, Available-for-Sale, Unrealized Gain	3.6	11.7
Debt Securities, Available-for-Sale, Unrealized Loss	26.9	37.4
Debt Securities, Available-for-Sale, Unrealized Loss Position	26.9	37.4
Entergy Arkansas [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	579.0	496.9
Debt Securities, Available-for-Sale, Unrealized Gain	1.2	2.4
Debt Securities, Available-for-Sale, Unrealized Loss	25.8	53.6
Debt Securities, Available-for-Sale, Unrealized Loss Position	25.8	53.6
System Energy [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	559.8	485.2
Debt Securities, Available-for-Sale, Unrealized Gain	1.9	4.5
Debt Securities, Available-for-Sale, Unrealized Loss	27.6	42.5
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 27.6	$ 42.5