Decommissioning Trust Funds (Securities Held) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Total	$ 1,660.0	$ 1,655.0
Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	222.0	201.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1.0	4.0
Total	1,660.0	1,655.0
Entergy Arkansas [Member]
Debt Securities, Available-for-sale [Line Items]
Total	470.9	470.7
Entergy Arkansas [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	78.1	69.3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0.1	0.2
Total	470.9	470.7
Entergy Louisiana [Member]
Debt Securities, Available-for-sale [Line Items]
Total	736.8	725.1
Entergy Louisiana [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	74.5	67.5
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1.3	3.5
Total	736.8	725.1
System Energy [Member]
Debt Securities, Available-for-sale [Line Items]
Total	452.8	459.7
System Energy [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	69.8	63.7
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0.1	0.7
Total	$ 452.8	$ 459.7