Decommissioning Trust Funds (Schedule of Available-for-Sale Securities Reconciliation) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	$ 1,922.0	$ 1,770.0
Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale, Unrealized Loss Position	139.0	134.0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	10.0	19.0
Debt Securities, Available-for-Sale	1,922.0	1,770.0
Entergy Arkansas [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	554.4	496.9
Entergy Arkansas [Member] | Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale, Unrealized Loss Position	59.0	53.6
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	1.9	2.4
Debt Securities, Available-for-Sale	554.4	496.9
Entergy Louisiana [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	812.6	788.1
Entergy Louisiana [Member] | Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale, Unrealized Loss Position	39.8	37.4
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	4.6	11.7
Debt Securities, Available-for-Sale	812.6	788.1
System Energy [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	554.6	485.2
System Energy [Member] | Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale, Unrealized Loss Position	40.2	42.5
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	3.2	4.5
Debt Securities, Available-for-Sale	$ 554.6	$ 485.2