Derivative Financial Instruments - Customer-related derivative positions (Detail) - Not Designated as Hedging Instrument $ in Thousands	Mar. 31, 2022 USD ($) position	Dec. 31, 2021 USD ($) position
Interest rate swaps
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	468	494
Total Notional | $	$ 2,867,637	$ 3,009,150
Risk participation agreements
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	63	64
Total Notional | $	$ 263,496	$ 238,772
Matched commercial customer book
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	70	72
Total Notional | $	$ 10,343	$ 7,922
Foreign currency loan
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	5	6
Total Notional | $	$ 11,586	$ 10,830