Decommissioning Trust Funds (Schedule of Available-for-Sale Securities Reconciliation) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	$ 2,466.0	$ 2,202.0
Debt Securities, Available-for-Sale, Unrealized Gain	13.0	28.0
Debt Securities, Available-for-Sale, Unrealized Loss	56.0	45.0
Entergy Arkansas [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	693.2	614.0
Debt Securities, Available-for-Sale, Unrealized Gain	2.7	7.5
Debt Securities, Available-for-Sale, Unrealized Loss	20.1	14.2
Entergy Louisiana [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	1,093.0	992.6
Debt Securities, Available-for-Sale, Unrealized Gain	7.6	13.0
Debt Securities, Available-for-Sale, Unrealized Loss	14.4	15.0
System Energy [Member]
Debt Securities, Available-for-Sale [Line Items]
Debt Securities, Available-for-Sale	679.6	595.0
Debt Securities, Available-for-Sale, Unrealized Gain	3.0	7.4
Debt Securities, Available-for-Sale, Unrealized Loss	$ 21.2	$ 16.2

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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+ Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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