Loans - Summary of Loan Balances (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	$ 6,708,666		$ 6,450,447
Total principal balance of loans owed, net of charge-offs	6,751,438		6,496,210
Unamortized net deferred loan fees	(16,674)		(15,275)
Discounts to principal balance of loans owed, net of charge-offs	(26,098)		(30,488)
Allowance for credit losses	(115,812)	$ (117,329)	(105,680)	$ (101,488)	$ (97,944)	$ (85,376)
Commercial Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	4,367,445		4,359,083
Allowance for credit losses	(66,675)	(71,016)	(61,381)	(58,640)	(55,450)	(51,140)
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	1,288,810		1,240,743
Allowance for credit losses	(26,618)	(26,513)	(24,639)	(23,932)	(23,931)	(23,474)
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	599,757		569,921
Allowance for credit losses	(12,290)	(11,647)	(13,597)	(10,400)	(9,979)	(3,862)
Construction
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	320,963		211,560
Allowance for credit losses	(8,097)	(7,031)	(5,142)	(6,132)	(7,522)	(5,667)
Agriculture production
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	123,472		61,414
Allowance for credit losses	(2,125)	(1,105)	(906)	(2,368)	(1,046)	(1,215)
Leases
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	8,219		7,726
Allowance for credit losses	(7)	(17)	(15)	(16)	(16)	(18)
CRE non-owner occupied | Commercial Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	2,171,422		2,149,725
Allowance for credit losses	(33,723)	(33,042)	(30,962)	(29,244)	(28,081)	(25,739)
CRE owner occupied | Commercial Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	958,054		984,807
Allowance for credit losses	(14,503)	(20,208)	(14,014)	(13,525)	(12,620)	(10,691)
Multifamily | Commercial Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	959,361		944,537
Allowance for credit losses	(14,239)	(14,075)	(13,132)	(12,749)	(11,795)	(12,395)
Farmland | Commercial Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	278,608		280,014
Allowance for credit losses	(4,210)	(3,691)	(3,273)	(3,122)	(2,954)	(2,315)
SFR 1-4 1st DT liens | Consumer
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	870,209		790,349
SFR HELOCs and junior liens | Consumer
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	352,798		393,666
Allowance for credit losses	(10,163)	(10,608)	(11,413)	(11,383)	(11,591)	(10,510)
Other | Consumer
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable	65,803		56,728
Allowance for credit losses	$ (2,920)	$ (2,771)	$ (1,958)	$ (1,878)	$ (2,029)	$ (2,241)