Loans and Allowance for Credit Losses - Rollforward of Allowance for Credit/Loan Losses by Portfolio Segment (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 196,711,000	$ 218,583,000
Charge-offs	(9,857,000)	(6,602,000)
Recoveries	1,479,000	1,292,000
Provision	(7,000,000)	(7,500,000)
Ending balance - ACL	181,333,000	205,773,000
Beginning balance - ACL on off-balance sheet	2,588,000	5,588,000
Provision	500,000	0
Ending balance - ACL on off-balance sheet	3,088,000	5,588,000
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	123,732,000	122,700,000
Charge-offs	(8,202,000)	(4,717,000)
Recoveries	661,000	126,000
Provision	2,477,000	1,459,000
Ending balance - ACL	118,668,000	119,568,000
Beginning balance - ACL on off-balance sheet	1,739,000	3,859,000
Provision	439,000
Ending balance - ACL on off-balance sheet	2,178,000	3,859,000
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	1,738,000	5,219,000
Recoveries		115,000
Provision	(877,000)	(661,000)
Ending balance - ACL	861,000	4,673,000
Beginning balance - ACL on off-balance sheet	160,000	287,000
Provision	26,000
Ending balance - ACL on off-balance sheet	186,000	287,000
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	56,265,000	61,931,000
Recoveries	362,000	509,000
Provision	(9,317,000)	(2,397,000)
Ending balance - ACL	47,310,000	60,043,000
Beginning balance - ACL on off-balance sheet	480,000	447,000
Provision	(62,000)
Ending balance - ACL on off-balance sheet	418,000	447,000
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	3,921,000	6,586,000
Charge-offs	(32,000)	(76,000)
Recoveries	28,000	59,000
Provision	120,000	(2,386,000)
Ending balance - ACL	4,037,000	4,183,000
Beginning balance - ACL on off-balance sheet	106,000	145,000
Provision	18,000
Ending balance - ACL on off-balance sheet	124,000	145,000
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	845,000	1,480,000
Charge-offs	(158,000)	(109,000)
Recoveries	29,000	23,000
Provision	(298,000)	(791,000)
Ending balance - ACL	418,000	603,000
Beginning balance - ACL on off-balance sheet		381,000
Provision	13,000
Ending balance - ACL on off-balance sheet	13,000	381,000
Credit Cards Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	6,075,000	15,786,000
Charge-offs	(1,465,000)	(1,692,000)
Recoveries	399,000	442,000
Provision	810,000	(2,392,000)
Ending balance - ACL	5,819,000	12,144,000
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	2,195,000	2,271,000
Charge-offs		(8,000)
Recoveries		18,000
Provision	(20,000)	(681,000)
Ending balance - ACL	2,175,000	1,600,000
Beginning balance - ACL on off-balance sheet	15,000	414,000
Provision	47,000
Ending balance - ACL on off-balance sheet	62,000	414,000
Total - Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	194,771,000	215,973,000
Charge-offs	(9,857,000)	(6,602,000)
Recoveries	1,479,000	1,292,000
Provision	(7,105,000)	(7,849,000)
Ending balance - ACL	179,288,000	202,814,000
Beginning balance - ACL on off-balance sheet	2,500,000	5,533,000
Provision	481,000
Ending balance - ACL on off-balance sheet	2,981,000	5,533,000
HTM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	1,940,000	2,610,000
Provision	105,000	349,000
Ending balance - ACL	2,045,000	2,959,000
Beginning balance - ACL on off-balance sheet	88,000	55,000
Provision	19,000
Ending balance - ACL on off-balance sheet	$ 107,000	$ 55,000