Decommissioning Trust Funds (Securities Held) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Total	$ 1,626.0	$ 2,177.0
Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	232.0	12.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2.0	65.0
Total	1,626.0	2,177.0
Entergy Arkansas [Member]
Debt Securities, Available-for-sale [Line Items]
Total	461.1	526.3
Entergy Arkansas [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	73.7	4.7
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0.0	11.4
Total	461.1	526.3
Entergy Louisiana [Member]
Debt Securities, Available-for-sale [Line Items]
Total	714.7	794.2
Entergy Louisiana [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	86.6	3.3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1.8	31.3
Total	714.7	794.2
System Energy [Member]
Debt Securities, Available-for-sale [Line Items]
Total	450.7	524.5
System Energy [Member] | Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	71.2	2.9
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0.1	11.8
Total	$ 450.7	$ 524.5