Decommissioning Trust Funds (Schedule of Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value) (Details) - Debt Securities [Member] - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 453.0	$ 134.0
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	949.0	999.0
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value	1,402.0	1,133.0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	5.0	6.0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	134.0	128.0
Debt Securities, Available-for-Sale, Unrealized Loss Position	139.0	134.0
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	70.8	22.5
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	388.7	403.4
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value	459.5	425.9
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	1.1	0.4
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	57.9	53.2
Debt Securities, Available-for-Sale, Unrealized Loss Position	59.0	53.6
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	275.6	69.8
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	340.4	356.1
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value	616.0	425.9
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	2.7	0.9
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	37.1	36.5
Debt Securities, Available-for-Sale, Unrealized Loss Position	39.8	37.4
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	106.8	42.1
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	219.8	239.1
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value	326.6	281.2
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months	1.6	4.5
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer	38.6	38.0
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 40.2	$ 42.5