Fair Value of Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	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)