Loans Held for Investment and Allowance for Loan Losses - Schedule of Non-Accrual Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	$ 38,812	$ 24,325	$ 24,604
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	3,365	5,057	5,966
Commercial [Member] | C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	3,365	5,057	5,966
Commercial [Member] | Muncipal [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	0	0	0
Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	838	324	338
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	34,038	18,484	17,677
Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	3,295	1,567	1,696
Real Estate [Member] | Farm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	5,534	85	91
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	8,407	2,321	2,406
Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	7,812	7,092	6,703
Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	8,990	7,419	6,781
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	571	460	623
Consumer [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	465	429	596
Consumer [Member] | Non-Auto [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	$ 106	$ 31	$ 27