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Fair Value of Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions | 12 Months Ended |
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
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 | 7.00% | 7.00% |  |
Percentage of level 3 liabilities at fair value in total liabilities measured at fair value | 99.00% | 82.00% |  |
Gain (loss) on cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option | $ (139) | $ (283) | $ 100 | $ 115
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 cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option | (1) | (45) | (32) | $ (51)
Gain (loss) on instrument-specific credit risk recognized in earnings | $ (45) | $ (18) | $ (36) |

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