Nuclear Decommissioning Trust Funds - Summary of Maturities for Available-for-sale Debt Securities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Maturities within one year	$ 82	$ 105
Maturities within two to five years	220	194
Maturities thereafter	309	280
Debt securities, fair value	$ 611	$ 579

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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