Loans and Allowance for Credit Losses - Rollforward of Allowance for Credit/Loan Losses by Portfolio Segment (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 222,996,000	$ 194,243,000
Charge-offs	(5,477,000)	(5,834,000)
Recoveries	2,460,000	1,191,000
Provision	10,000,000	23,250,000
Ending balance - ACL	229,979,000	212,850,000
Beginning balance - ACL on off-balance sheet	5,088,000	3,088,000
Provision	0	0
Ending balance - ACL on off-balance sheet	5,088,000	3,088,000
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	155,658,000	136,737,000
Charge-offs	(944,000)	(2,819,000)
Recoveries	1,252,000	788,000
Provision	(16,142,000)	19,778,000
Ending balance - ACL	139,824,000	154,484,000
Beginning balance - ACL on off-balance sheet	4,092,000	2,178,000
Ending balance - ACL on off-balance sheet	4,092,000	2,178,000
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recoveries	1,000	1,000
Provision	(1,000)	921,000
Ending balance - ACL		922,000
Beginning balance - ACL on off-balance sheet	186,000	186,000
Ending balance - ACL on off-balance sheet	186,000	186,000
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	45,507,000	39,370,000
Charge-offs	(250,000)	(21,000)
Provision	21,034,000	1,165,000
Ending balance - ACL	66,291,000	40,514,000
Beginning balance - ACL on off-balance sheet	460,000	418,000
Ending balance - ACL on off-balance sheet	460,000	418,000
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	6,941,000	6,148,000
Charge-offs	(174,000)	(1,121,000)
Recoveries	606,000	13,000
Provision	(3,974,000)	576,000
Ending balance - ACL	3,399,000	5,616,000
Beginning balance - ACL on off-balance sheet	117,000	124,000
Ending balance - ACL on off-balance sheet	117,000	124,000
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	1,089,000	494,000
Charge-offs	(408,000)	(269,000)
Recoveries	76,000	22,000
Provision	(226,000)	206,000
Ending balance - ACL	531,000	453,000
Beginning balance - ACL on off-balance sheet	9,000	13,000
Ending balance - ACL on off-balance sheet	9,000	13,000
Credit Cards Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	7,935,000	6,866,000
Charge-offs	(3,701,000)	(1,604,000)
Recoveries	525,000	367,000
Provision	9,798,000	842,000
Ending balance - ACL	14,557,000	6,471,000
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	2,608,000	2,221,000
Provision	(1,051,000)	(172,000)
Ending balance - ACL	1,557,000	2,049,000
Beginning balance - ACL on off-balance sheet	160,000	62,000
Ending balance - ACL on off-balance sheet	160,000	62,000
Total - Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	219,738,000	191,836,000
Charge-offs	(5,477,000)	(5,834,000)
Recoveries	2,460,000	1,191,000
Provision	9,438,000	23,316,000
Ending balance - ACL	226,159,000	210,509,000
Beginning balance - ACL on off-balance sheet	5,024,000	2,981,000
Ending balance - ACL on off-balance sheet	5,024,000	2,981,000
HTM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	3,258,000	2,407,000
Provision	562,000	(66,000)
Ending balance - ACL	3,820,000	2,341,000
Beginning balance - ACL on off-balance sheet	64,000	107,000
Ending balance - ACL on off-balance sheet	$ 64,000	$ 107,000