Derivative Instruments - Summary of Effective Portion of Gains (Losses) Recognized in Other Comprehensive Income (Loss) and Gains (Losses) Reclassified from Other Comprehensive Income (Loss) into Earnings (Detail) - Asset and Liability Management Positions [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Cash Flow Hedges [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Losses) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (259)	$ (173)	$ (453)	$ (100)
Derivative Instruments, Gains (Losses) Reclassified from Other Comprehensive Income (Loss) into Earnings	(20)	(6)	(34)	(22)
Net Investment Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Losses) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	15	37	6	63
Derivative Instruments, Gains (Losses) Reclassified from Other Comprehensive Income (Loss) into Earnings Net	0	0	0	0
Net Investment Hedges [Member] | Non Derivative Debt Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Losses) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	24	56	7	139
Derivative Instruments, Gains (Losses) Reclassified from Other Comprehensive Income (Loss) into Earnings Net	$ 0	$ 0	$ 0	$ 0