Trust Investments - Fair Values And Gross Unrealized Gains And Losses For The Securities Held (Parenthetical) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Nuclear Decommissioning Trust (NDT) Fund [Member]
Debt Securities, Available-for-Sale [Line Items]
NDT Fund Foreign Currency	$ 30	$ 24

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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+ Details