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Fair Value of Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2024 | Jun. 30, 2024 | Jun. 30, 2025 | Dec. 31, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |
Percentage of level 3 assets at fair value in total assets measured at fair value value |  |  | 6.00% | 5.00%
Percentage of level 3 liabilities at fair value in total liabilities measured at fair value |  |  | 99.00% | 99.00%
Gain (loss) on cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option |  |  | $ (2,178) | $ (2,089)
Accumulated Other Comprehensive Income [Member] |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |
Gain (loss) on cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option |  |  | (96) | (128)
Instrument-specific credit risk of liabilities measured at fair value, net [Member] |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |
Gain (loss) on instrument-specific credit risk recognized in earnings | $ 9 | $ 28 |  |
Instrument-specific credit risk of liabilities measured at fair value, net [Member] | Accumulated Other Comprehensive Income [Member] |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |
Gain (loss) on cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option |  |  | 29 | 27
Cross Currency Swap [Member] |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |
Derivative notional amount |  |  | $ 30 | $ 36

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