Derivative Instruments - Summary of Gains (Losses) Recognized in Earnings for Other Economic Hedges and Customer-Related Positions (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Noninterest Income	Noninterest Income	Noninterest Income	Noninterest Income
Customer-Related Positions [Member] | Interest Rate Contracts [Member] | Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	$ (1)			$ 4
Customer-Related Positions [Member] | Interest Rate Contracts [Member] | Futures [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings		$ 8	$ (1)	24
Customer-Related Positions [Member] | Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	58	3	95	47
Customer-Related Positions [Member] | Foreign Exchange Rate Contracts [Member] | Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings		1		1
Customer-Related Positions [Member] | Foreign Exchange Rate Contracts [Member] | Forwards, Spots and Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	44	20	99	35
Customer-Related Positions [Member] | Commodity Contract [Member] | Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	2		2
Customer-Related Positions [Member] | Credit Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(1)	17	(1)	22
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Futures and Forwards [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	31	74	38	297
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	17	6	15	(41)
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(38)	(247)	20	(451)
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(8)	4	(13)	1
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Equity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	0	(1)	(3)	$ (3)
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Other Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	$ 1	$ 1	$ (1)