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Fair Value of Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 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		5.00%	5.00%
Percentage of level 3 liabilities at fair value in total liabilities measured at fair value		100.00%	99.00%
Gain (loss) on cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option		$ (2,180)	$ (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		(89)	(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	$ 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		25	27
Cross Currency Swap [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative notional amount		$ 29	$ 36

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