Derivative Financial Instruments - Schedule of Notional Amounts and Estimated Fair Values of Interest Rate Derivative Contracts Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 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
Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Securities Interest Rate Swaps Liability
Derivatives, Fair Value [Line Items]
Forward Contracts – Liability Notional Amount	500,000	$ 0
Estimated Fair Value	(204)	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	2,045,121	783,022
Estimated Fair Value	80,083	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	215,572	1,341,227
Estimated Fair Value	(578)	(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	286,977	251,075
Estimated Fair Value	5,127	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	215,572	1,341,227
Estimated Fair Value	578	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	2,045,121	783,022
Estimated Fair Value	(80,083)	(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	286,977	251,075
Estimated Fair Value	$ (5,130)	$ (3,232)

Nominal or face amount used to calculate payments on the derivative asset.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Nominal or face amount used to calculate payments on the derivative liability.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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