Derivative Financial Instruments - Schedule of Notional Amounts and Estimated Fair Values of Interest Rate Derivative Contracts Outstanding (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Designated as Hedging Instrument [Member] | Financial Institution Counterparties Securities Interest Rate Swaps Assets
Derivatives, Fair Value [Line Items]
Forward Contracts – Assets Notional Amount	$ 500,000	$ 0
Estimated Fair Value	198	0
Non Designated as Hedging Instrument [Member] | Financial institution counterparties Loan/lease interest rate swaps assets [Member]
Derivatives, Fair Value [Line Items]
Forward Contracts – Assets Notional Amount	1,185,210	783,022
Estimated Fair Value	35,575	34,835
Non Designated as Hedging Instrument [Member] | Financial institution counterparties Loan/lease interest rate swaps liabilities [Member]
Derivatives, Fair Value [Line Items]
Forward Contracts – Liability Notional Amount	1,067,240	1,341,227
Estimated Fair Value	(13,819)	(20,598)
Non Designated as Hedging Instrument [Member] | Financial institution counterparties Loan/lease interest-rate caps assets [Member]
Derivatives, Fair Value [Line Items]
Forward Contracts – Assets Notional Amount	249,789	251,075
Estimated Fair Value	3,370	3,230
Non Designated as Hedging Instrument [Member] | Customer counterparties Loan/lease interest rate swaps assets [Member]
Derivatives, Fair Value [Line Items]
Forward Contracts – Assets Notional Amount	1,067,240	1,341,227
Estimated Fair Value	13,819	20,598
Non Designated as Hedging Instrument [Member] | Customer counterparties Loan/lease interest rate swaps liabilities [Member]
Derivatives, Fair Value [Line Items]
Forward Contracts – Liability Notional Amount	1,185,210	783,022
Estimated Fair Value	(35,575)	(34,835)
Non Designated as Hedging Instrument [Member] | Customer counterparties Loan/lease interest rate caps liabilities [Member]
Derivatives, Fair Value [Line Items]
Forward Contracts – Liability Notional Amount	249,789	251,075
Estimated Fair Value	$ (3,371)	$ (3,232)