Loans Held-for-Investment and Allowance for Credit Losses - Schedule of Investment in Loans Related to Balance in Allowance for Loan Losses on Basis of Company's Impairment Methodology (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	$ 245,612	$ 233,851	$ 201,587
Loans collectively evaluated for credit losses	7,699,999	7,679,247	7,027,823
Total Loans	7,945,611	7,913,098	7,229,410
C&I [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	28,547	29,762	41,454
Loans collectively evaluated for credit losses	1,115,882	1,147,231	1,150,062
Total Loans	1,144,429	1,176,993	1,191,516
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	9,601	409	559
Loans collectively evaluated for credit losses	328,702	368,837	210,454
Total Loans	338,303	369,246	211,013
Construction & Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	10,327	11,174	30,929
Loans collectively evaluated for credit losses	1,087,742	1,043,429	890,844
Total Loans	1,098,069	1,054,603	921,773
Farm [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	10,936	10,588	6,533
Loans collectively evaluated for credit losses	320,528	329,077	304,469
Total Loans	331,464	339,665	311,002
Non-Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	39,726	39,894	31,655
Loans collectively evaluated for credit losses	714,172	765,672	822,066
Total Loans	753,898	805,566	853,721
Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	78,640	79,470	41,179
Loans collectively evaluated for credit losses	1,063,978	1,003,630	991,666
Total Loans	1,142,618	1,083,100	1,032,845
Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	59,382	53,659	39,271
Loans collectively evaluated for credit losses	2,158,358	2,143,108	1,879,302
Total Loans	2,217,740	2,196,767	1,918,573
Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	3,828	3,579	2,828
Loans collectively evaluated for credit losses	675,361	634,981	547,009
Total Loans	679,189	638,560	549,837
Non-Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	1,191	1,105	1,092
Loans collectively evaluated for credit losses	148,524	151,950	150,156
Total Loans	149,715	153,055	151,248
Agriculture [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	3,434	4,211	6,087
Loans collectively evaluated for credit losses	86,752	91,332	81,795
Total Loans	90,186	95,543	87,882
Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	199,011	194,785	149,567
Total Loans	5,543,789	5,479,701	5,037,914
Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	10,327	11,174	30,929
Total Loans	1,098,069	1,054,603	921,773
Real Estate [Member] | Farm [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	10,936	10,588	6,533
Total Loans	331,464	339,665	311,002
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	39,726	39,894	31,655
Total Loans	753,898	805,566	853,721
Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	78,640	79,470	41,179
Total Loans	1,142,618	1,083,100	1,032,845
Real Estate [Member] | Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	59,382	53,659	39,271
Total Loans	2,217,740	2,196,767	1,918,573
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	5,019	4,684	3,920
Total Loans	828,904	791,615	701,085
Consumer [Member] | Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	3,828	3,579	2,828
Total Loans	679,189	638,560	549,837
Consumer [Member] | Non-Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	1,191	1,105	1,092
Total Loans	$ 149,715	$ 153,055	$ 151,248