Allowance for Credit Losses - Summary of Activity in Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	$ 117,329	$ 97,944	$ 105,680	$ 85,376	$ 85,376
Charge-offs	(5,357)	(267)	(7,391)	(1,411)	(1,585)
Recoveries	720	311	1,108	1,841	1,907
Provision (benefit)	3,120	3,500	16,415	13,645	17,945
Ending  Balance	115,812	101,488	115,812	101,488	105,680
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning Balance	4,865	4,075	4,315	3,790	3,790
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (benefit)	1,035	295	1,585	580	525
Ending  Balance	5,900	4,370	5,900	4,370	4,315
Credit Loss [Roll Forward]
Beginning Balance	122,194	102,019	109,995	89,166	89,166
Charge-offs	(5,357)	(267)	(7,391)	(1,411)	(1,585)
Recoveries	720	311	1,108	1,841	1,907
Provision (benefit)	4,155	3,795	18,000	14,225	18,470
Ending  Balance	121,712	105,858	121,712	105,858	109,995
ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				2,037	2,037
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning Balance				0	0
Credit Loss [Roll Forward]
Beginning Balance				2,037	2,037
Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	71,016	55,450	61,381	51,140	51,140
Charge-offs	(3,608)	0	(3,608)	(294)	(294)
Recoveries	0	2	1	3	3
Provision (benefit)	(733)	3,188	8,901	6,218	8,959
Ending  Balance	66,675	58,640	66,675	58,640	61,381
Commercial Real Estate | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				1,573	1,573
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	26,513	23,931	24,639	23,474	23,474
Charge-offs	(133)	(185)	(480)	(470)	(594)
Recoveries	628	189	807	705	743
Provision (benefit)	(390)	(3)	1,652	79	872
Ending  Balance	26,618	23,932	26,618	23,932	24,639
Consumer | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				144	144
Commercial and industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	11,647	9,979	13,597	3,862	3,862
Charge-offs	(1,616)	(82)	(3,303)	(647)	(697)
Recoveries	91	119	267	1,130	1,157
Provision (benefit)	2,168	384	1,729	5,974	9,194
Ending  Balance	12,290	10,400	12,290	10,400	13,597
Commercial and industrial | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				81	81
Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	7,031	7,522	5,142	5,667	5,667
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (benefit)	1,066	(1,390)	2,955	264	(726)
Ending  Balance	8,097	6,132	8,097	6,132	5,142
Construction | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				201	201
Agriculture production
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	1,105	1,046	906	1,215	1,215
Charge-offs	0	0	0	0	0
Recoveries	1	1	33	3	4
Provision (benefit)	1,019	1,321	1,186	1,112	(351)
Ending  Balance	2,125	2,368	2,125	2,368	906
Agriculture production | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				38	38
Leases
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	17	16	15	18	18
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (benefit)	(10)	0	(8)	(2)	(3)
Ending  Balance	7	16	7	16	15
Leases | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				0	0
CRE non-owner occupied | Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	33,042	28,081	30,962	25,739	25,739
Charge-offs	0	0	0	0	0
Recoveries	0	1	0	1	1
Provision (benefit)	681	1,162	2,761	2,758	4,476
Ending  Balance	33,723	29,244	33,723	29,244	30,962
CRE non-owner occupied | Commercial Real Estate | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				746	746
CRE owner occupied | Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	20,208	12,620	14,014	10,691	10,691
Charge-offs	(3,608)	0	(3,608)	0	0
Recoveries	0	1	1	2	2
Provision (benefit)	(2,097)	904	4,096	2,769	3,258
Ending  Balance	14,503	13,525	14,503	13,525	14,014
CRE owner occupied | Commercial Real Estate | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				63	63
Multifamily | Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	14,075	11,795	13,132	12,395	12,395
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (benefit)	164	954	1,107	354	737
Ending  Balance	14,239	12,749	14,239	12,749	13,132
Multifamily | Commercial Real Estate | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				0	0
Farmland | Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	3,691	2,954	3,273	2,315	2,315
Charge-offs	0	0	0	(294)	(294)
Recoveries	0	0	0	0	0
Provision (benefit)	519	168	937	337	488
Ending  Balance	4,210	3,122	4,210	3,122	3,273
Farmland | Commercial Real Estate | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				764	764
SFR 1-4 1st DT liens | Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	13,134	10,311	11,268	10,723	10,723
Charge-offs	0	0	0	0	0
Recoveries	262	38	262	79	79
Provision (benefit)	139	322	2,005	(275)	322
Ending  Balance	13,535	10,671	13,535	10,671	11,268
SFR 1-4 1st DT liens | Consumer | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				144	144
SFR HELOCs and junior liens | Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	10,608	11,591	11,413	10,510	10,510
Charge-offs	0	0	(42)	0	(22)
Recoveries	314	98	416	426	429
Provision (benefit)	(759)	(306)	(1,624)	447	496
Ending  Balance	10,163	11,383	10,163	11,383	11,413
SFR HELOCs and junior liens | Consumer | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				0	0
Other | Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	2,771	2,029	1,958	2,241	2,241
Charge-offs	(133)	(185)	(438)	(470)	(572)
Recoveries	52	53	129	200	235
Provision (benefit)	230	(19)	1,271	(93)	54
Ending  Balance	$ 2,920	$ 1,878	$ 2,920	1,878	1,958
Other | Consumer | ACL of PCD Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				$ 0	$ 0