Decommissioning Trust Funds (Available For Sale Securities Continuous Unrealized Loss Position Fair Value) (Details) - Debt Securities [Member] - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 1,357.0	$ 770.0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	123.0	99.0
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	1,480.0	869.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	134.0	8.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	23.0	4.0
Debt Securities, Available-for-sale, Unrealized Loss Position	157.0	12.0
Entergy Arkansas [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	384.2	183.8
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	64.2	39.5
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	448.4	223.3
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	40.8	2.9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	11.4	1.8
Debt Securities, Available-for-sale, Unrealized Loss Position	52.2	4.7
Entergy Louisiana [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	528.8	206.9
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	41.8	42.9
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	570.6	249.8
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	48.5	1.4
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	7.5	1.9
Debt Securities, Available-for-sale, Unrealized Loss Position	56.0	3.3
System Energy [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	443.6	276.6
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	16.7	11.3
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	460.3	287.9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	45.1	2.3
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	4.1	0.6
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 49.2	$ 2.9

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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