Derivative Instruments - Summary of Gains (Losses) Recognized in Earnings for Other Economic Hedges and Customer-Related Positions (Detail) - Asset and Liability Management Positions [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Credit Contracts [Member] | Commercial Products Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	$ 5	$ 2
Foreign Exchange Rate Contracts [Member] | Commercial Products Revenue [Member] | Forwards, Spots and Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	15	19
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Mortgage Banking Revenue [Member] | Futures and Forwards [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	223	430
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Mortgage Banking Revenue [Member] | Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(47)	12
Other Economic Hedges [Member] | Swaps [Member] | Mortgage Banking Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(204)	(390)
Other Economic Hedges [Member] | Equity Contracts [Member] | Compensation Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(2)	4
Other Economic Hedges [Member] | Other Derivatives [Member] | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(1)
Other Economic Hedges [Member] | Foreign Exchange Rate Contracts [Member] | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	(3)	(3)
Customer-Related Positions [Member] | Interest Rate Contracts [Member] | Commercial Products Revenue [Member] | Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	4	(7)
Customer-Related Positions [Member] | Interest Rate Contracts [Member] | Commercial Products Revenue [Member] | Futures [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	16
Customer-Related Positions [Member] | Swaps [Member] | Commercial Products Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in earnings	$ 17	$ 27