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Derivative Financial Instruments - Information about Hedged Items Included in Consolidated Balance Sheet (Detail) - Designated as Hedging Instrument - USD ($) $ in Millions | Sep. 30, 2024 | Dec. 31, 2023
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Carrying Amount | Long-term Debt |  |
Derivatives, Fair Value [Line Items] |  |
Hedged Item | $ 3,853 | $ 2,954
Carrying Amount | Debt Securities, Available For Sale |  |
Derivatives, Fair Value [Line Items] |  |
Hedged Item | 391 |
Estimated Fair Value | Long-term Debt |  |
Derivatives, Fair Value [Line Items] |  |
Hedged Item | $ 8 | $ (44)

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