Loans and the Allowance for Credit Losses - Summary of Loans with FDMs (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	$ 312	$ 190	$ 3,786
Payment Delay [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	312		318
Term Extension [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted		190	3,468
Commercial and Industrial [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted		190
Commercial and Industrial [Member] \| Term Extension [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted		$ 190
Commercial Real Estate [Member] \| Commercial Real Estate - Improved Property [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted			3,468
Commercial Real Estate [Member] \| Commercial Real Estate - Improved Property [Member] \| Term Extension [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted			3,468
Residential Real Estate [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	123		123
Residential Real Estate [Member] \| Payment Delay [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	123		123
Home Equity [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	109		115
Home Equity [Member] \| Payment Delay [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	109		115
Consumer [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	80		80
Consumer [Member] \| Payment Delay [Member]
Financing Receivable, Modified [Line Items]
Loans that subsequently defaulted	$ 80		$ 80