Derivative Financial Instruments - Customer-related derivative positions (Detail) $ in Thousands	Sep. 30, 2022 USD ($) position	Dec. 31, 2021 USD ($) position
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Total Notional	$ 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	400	494
Total Notional	$ 2,549,355	$ 3,009,150
Risk participation agreements | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	60	64
Total Notional	$ 252,553	$ 238,772
Matched commercial customer book | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	72	72
Total Notional	$ 12,016	$ 7,922
Foreign currency loan | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions | position	4	6
Total Notional	$ 12,030	$ 10,830