Derivative Financial Instruments - Company's derivative financial instruments included in OCI as follows (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain in OCI on derivatives	$ 0	$ 0
Gain reclassified from OCI into interest income (effective portion)	5,298	8,274
Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test)	0	0
(Loss) gain recognized in other income for foreign currency exchange contracts:	2,434	5,299
Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
Gain reclassified from OCI into interest income (effective portion)	5,298	8,274
Interest Income | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test)	0	0
Interest Income | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Customer-related positions:	2,298	4,851
Interest Income | Risk participation agreements
Derivative Instruments, Gain (Loss) [Line Items]
Customer-related positions:	60	369
Other Income
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test)	0	0
Other Income | Foreign currency exchange contracts – matched customer book
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain recognized in other income for foreign currency exchange contracts:	(2)	6
Other Income | Foreign currency exchange contracts – foreign currency loan
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain recognized in other income for foreign currency exchange contracts:	$ 78	$ 73