Fair Value of Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
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%		6.00%		7.00%
Percentage of level 3 liabilities at fair value in total liabilities measured at fair value	85.00%		85.00%		82.00%
Gain (loss) on cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option	$ (263)		$ (263)		$ (283)
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	(4)		(4)		$ (45)
Gain (loss) on instrument-specific credit risk recognized in earnings	$ (11)	$ (23)	$ (45)	$ (11)