Loans Held for Investment and Allowance for Loan Losses - Loans Held-for-Investment by Class of Financing Receivables (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	$ 7,723,191	$ 7,148,791	$ 6,994,696
Less-Allowance for credit losses	(99,936)	(88,734)	(89,714)
Net loans held-for-investment	7,623,255	7,060,057	6,904,982
C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,175,774	1,164,811	1,108,240
Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	333,732	214,850	218,358
Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,013,810	963,158	929,570
Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	315,720	344,954	341,052
Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	825,928	827,969	828,900
Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,086,750	1,037,281	1,002,913
Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	2,112,196	1,834,593	1,788,913
Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	618,103	521,859	540,382
Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	157,909	154,426	154,492
Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,509,506	1,379,661	1,326,598
Commercial [Member] | C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,175,774	1,164,811	1,108,240
Commercial [Member] | Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	333,732	214,850	218,358
Agriculture [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	83,269	84,890	81,876
Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	5,354,404	5,007,955	4,891,348
Real Estate [Member] | Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,013,810	963,158	929,570
Real Estate [Member] | Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	315,720	344,954	341,052
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	825,928	827,969	828,900
Real Estate [Member] | Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,086,750	1,037,281	1,002,913
Real Estate [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	2,112,196	1,834,593	1,788,913
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	776,012	676,285	694,874
Net loans held-for-investment	7,623,255	7,060,057	6,904,982
Consumer [Member] | Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	618,103	521,859	540,382
Consumer [Member] | Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	$ 157,909	$ 154,426	$ 154,492