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	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	$ 257,065	$ 233,851	$ 219,263
Loans collectively evaluated for credit losses	7,817,879	7,679,247	7,300,470
Total Loans	8,074,944	7,913,098	7,519,733
C&I [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	40,809	29,762	42,542
Loans collectively evaluated for credit losses	1,161,342	1,147,231	1,099,448
Total Loans	1,202,151	1,176,993	1,141,990
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	9,451	409	559
Loans collectively evaluated for credit losses	296,689	368,837	358,565
Total Loans	306,140	369,246	359,124
Construction & Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	16,620	11,174	26,681
Loans collectively evaluated for credit losses	1,156,214	1,043,429	959,713
Total Loans	1,172,834	1,054,603	986,394
Farm [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	10,321	10,588	9,795
Loans collectively evaluated for credit losses	292,648	329,077	308,802
Total Loans	302,969	339,665	318,597
Non-Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	40,126	39,894	30,496
Loans collectively evaluated for credit losses	706,215	765,672	785,217
Total Loans	746,341	805,566	815,713
Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	73,014	79,470	67,453
Loans collectively evaluated for credit losses	1,051,596	1,003,630	982,262
Total Loans	1,124,610	1,083,100	1,049,715
Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	59,112	53,659	34,643
Loans collectively evaluated for credit losses	2,227,108	2,143,108	1,955,961
Total Loans	2,286,220	2,196,767	1,990,604
Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	3,621	3,579	3,083
Loans collectively evaluated for credit losses	695,276	634,981	612,109
Total Loans	698,897	638,560	615,192
Non-Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	1,038	1,105	1,015
Loans collectively evaluated for credit losses	147,611	151,950	155,203
Total Loans	148,649	153,055	156,218
Agriculture [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	2,953	4,211	2,996
Loans collectively evaluated for credit losses	83,180	91,332	83,190
Total Loans	86,133	95,543	86,186
Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	199,193	194,785	169,068
Total Loans	5,632,974	5,479,701	5,161,023
Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	16,620	11,174	26,681
Total Loans	1,172,834	1,054,603	986,394
Real Estate [Member] | Farm [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	10,321	10,588	9,795
Total Loans	302,969	339,665	318,597
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	40,126	39,894	30,496
Total Loans	746,341	805,566	815,713
Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	73,014	79,470	67,453
Total Loans	1,124,610	1,083,100	1,049,715
Real Estate [Member] | Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	59,112	53,659	34,643
Total Loans	2,286,220	2,196,767	1,990,604
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	4,659	4,684	4,098
Total Loans	847,546	791,615	771,410
Consumer [Member] | Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	3,621	3,579	3,083
Total Loans	698,897	638,560	615,192
Consumer [Member] | Non-Auto [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually evaluated for credit losses	1,038	1,105	1,015
Total Loans	$ 148,649	$ 153,055	$ 156,218