Loans and the Allowance for Credit Losses - Summary of Changes in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	$ 121,622	$ 185,827
Allowance for credit losses - loan commitments, beginning balance	7,775	9,514
Total beginning allowance for credit losses - loans and loan commitments	129,397	195,341
Provision for loan losses	(5,907)	(48,422)
Provision for loan commitments	1,163	(2,224)
Total provision for credit losses - loans and loan commitments	(4,744)	(50,646)
Charge-offs	(5,972)	(7,038)
Recoveries	4,841	6,238
Net (charge-offs) recoveries	1,131	(800)
Allowance for credit losses - loans, ending balance	114,584	136,605
Allowance for credit losses - loan commitments, ending balance	8,938	7,290
Total ending allowance for credit losses - loans and loan commitments	123,522	143,895
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	26,875	37,850
Allowance for credit losses - loan commitments, beginning balance	1,497	1,275
Total beginning allowance for credit losses - loans and loan commitments	28,372	39,125
Provision for loan losses	2,160	(10,669)
Provision for loan commitments	(1,214)	451
Total provision for credit losses - loans and loan commitments	946	(10,218)
Charge-offs	(983)	(1,717)
Recoveries	871	1,737
Net (charge-offs) recoveries	112	20
Allowance for credit losses - loans, ending balance	28,923	27,201
Allowance for credit losses - loan commitments, ending balance	283	1,726
Total ending allowance for credit losses - loans and loan commitments	29,206	28,927
Deposit Overdrafts [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	2,220	639
Total beginning allowance for credit losses - loans and loan commitments	2,220	639
Provision for loan losses	260	1,709
Total provision for credit losses - loans and loan commitments	260	1,709
Charge-offs	(1,215)	(932)
Recoveries	278	264
Net (charge-offs) recoveries	937	(668)
Allowance for credit losses - loans, ending balance	1,543	1,680
Total ending allowance for credit losses - loans and loan commitments	1,543	1,680
Commercial Real Estate [Member] | Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	7,310	10,841
Allowance for credit losses - loan commitments, beginning balance	4,180	6,508
Total beginning allowance for credit losses - loans and loan commitments	11,490	17,349
Provision for loan losses	1,369	(3,665)
Provision for loan commitments	1,618	(2,829)
Total provision for credit losses - loans and loan commitments	2,987	(6,494)
Charge-offs	(73)	(22)
Recoveries	25	110
Net (charge-offs) recoveries	48	(88)
Allowance for credit losses - loans, ending balance	8,631	7,264
Allowance for credit losses - loan commitments, ending balance	5,798	3,679
Total ending allowance for credit losses - loans and loan commitments	14,429	10,943
Commercial Real Estate [Member] | Commercial Real Estate - Improved Property [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	65,355	110,652
Allowance for credit losses - loan commitments, beginning balance	201	712
Total beginning allowance for credit losses - loans and loan commitments	65,556	111,364
Provision for loan losses	(12,082)	(29,171)
Provision for loan commitments	(201)	(394)
Total provision for credit losses - loans and loan commitments	(12,283)	(29,565)
Charge-offs	(642)	(933)
Recoveries	899	1,053
Net (charge-offs) recoveries	(257)	120
Allowance for credit losses - loans, ending balance	53,530	81,601
Allowance for credit losses - loan commitments, ending balance		318
Total ending allowance for credit losses - loans and loan commitments	53,530	81,919
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	15,401	17,851
Allowance for credit losses - loan commitments, beginning balance	1,576	955
Total beginning allowance for credit losses - loans and loan commitments	16,977	18,806
Provision for loan losses	1,133	(3,481)
Provision for loan commitments	788	254
Total provision for credit losses - loans and loan commitments	1,921	(3,227)
Charge-offs	(282)	(842)
Recoveries	483	885
Net (charge-offs) recoveries	(201)	43
Allowance for credit losses - loans, ending balance	16,735	14,413
Allowance for credit losses - loan commitments, ending balance	2,364	1,209
Total ending allowance for credit losses - loans and loan commitments	19,099	15,622
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	3,737	6,507
Allowance for credit losses - loan commitments, beginning balance	272	19
Total beginning allowance for credit losses - loans and loan commitments	4,009	6,526
Provision for loan losses	1,216	(2,268)
Provision for loan commitments	165	287
Total provision for credit losses - loans and loan commitments	1,381	(1,981)
Charge-offs	(2,511)	(2,210)
Recoveries	1,992	1,718
Net (charge-offs) recoveries	519	(492)
Allowance for credit losses - loans, ending balance	4,434	3,747
Allowance for credit losses - loan commitments, ending balance	437	306
Total ending allowance for credit losses - loans and loan commitments	4,871	4,053
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - loans, beginning balance	724	1,487
Allowance for credit losses - loan commitments, beginning balance	49	45
Total beginning allowance for credit losses - loans and loan commitments	773	1,532
Provision for loan losses	37	(877)
Provision for loan commitments	7	7
Total provision for credit losses - loans and loan commitments	44	(870)
Charge-offs	(266)	(382)
Recoveries	293	471
Net (charge-offs) recoveries	(27)	89
Allowance for credit losses - loans, ending balance	788	699
Allowance for credit losses - loan commitments, ending balance	56	52
Total ending allowance for credit losses - loans and loan commitments	$ 844	$ 751