Derivative Financial Instruments - Customer-related derivative positions (Detail) $ in Thousands	Jun. 30, 2023 USD ($) position	Dec. 31, 2022 USD ($) position
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Total Notional	$ 2,400,000	$ 2,400,000
Interest rate swaps | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	372	382
Total Notional	$ 2,392,177	$ 2,404,003
Risk participation agreements | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	69	63
Total Notional	$ 264,719	$ 241,029
Matched commercial customer book | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	54	32
Total Notional	$ 8,682	$ 7,877
Foreign currency loan | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	7	5
Total Notional	$ 16,845	$ 13,948