Decommissioning Trust Funds (Securities Held) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Total	$ 1,655.0	$ 2,177.0
Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total	1,655.0	2,177.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4.0	65.0
Debt Securities, Available-for-sale, Unrealized Loss Position	201.0	12.0
Entergy Louisiana [Member]
Debt Securities, Available-for-sale [Line Items]
Total	725.1	794.2
Entergy Louisiana [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total	725.1	794.2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3.5	31.3
Debt Securities, Available-for-sale, Unrealized Loss Position	67.5	3.3
Entergy Arkansas [Member]
Debt Securities, Available-for-sale [Line Items]
Total	470.7	526.3
Entergy Arkansas [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total	470.7	526.3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0.2	11.4
Debt Securities, Available-for-sale, Unrealized Loss Position	69.3	4.7
System Energy [Member]
Debt Securities, Available-for-sale [Line Items]
Total	459.7	524.5
System Energy [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Total	459.7	524.5
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0.7	11.8
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 63.7	$ 2.9