Decommissioning Trust Funds (Securities Held) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Total	$ 1,770.0	$ 1,655.0
Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	1,770.0	1,655.0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	19.0	4.0
Debt Securities, Available-for-Sale, Unrealized Loss Position	134.0	201.0
Entergy Louisiana [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	788.1	725.1
Entergy Louisiana [Member] | Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	788.1	725.1
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	11.7	3.5
Debt Securities, Available-for-Sale, Unrealized Loss Position	37.4	67.5
Entergy Arkansas [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	496.9	470.7
Entergy Arkansas [Member] | Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	496.9	470.7
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	2.4	0.2
Debt Securities, Available-for-Sale, Unrealized Loss Position	53.6	69.3
System Energy [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	485.2	459.7
System Energy [Member] | Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Total	485.2	459.7
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	4.5	0.7
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 42.5	$ 63.7