Commitments, Contingencies and Guarantees - Notional Amount of Off-Balance Sheet Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Commitments to extend credit for loans (excluding credit card loans) [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	$ 12,687,851	$ 12,831,831
Commitments to extend credit under credit card loans [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	5,298,162	4,286,604
Commercial letters of credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	885	1,224
Standby letters of credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	431,331	407,574
Forward contracts [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	40,215	26,471
Spot foreign exchange contracts [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	74,984	$ 4,830
Commitments to extend credit for securities purchased under agreements to resell [Member]
Commitments and Contingencies Disclosure [Line Items]
Contractual or notional amount of off-balance sheet financial instruments	$ 300,000