Loans Held for Investment and Allowance for Loan Losses - Schedule of loans that are individually evaluated for credit losses (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Financing Receivable, Impaired [Line Items]
Related Allowance	$ 19,077	$ 17,573	$ 16,845
Total Recorded Investment	201,587	176,213	157,056
Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	11,453	12,626	11,867
Recorded Investment With Allowance	24,704	20,983	12,304
Related Allowance	5,301	3,791	4,434
Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	13,776	13,782	12,411
Total Recorded Investment	165,430	142,604	132,885
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	5,711	5,858	7,523
Total Recorded Investment	42,013	23,498	26,391
Commercial [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	3,194	1,322	0
Recorded Investment With Allowance	756	2,810	5,343
Related Allowance	1,541	1,363	3,582
Commercial [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	4,170	4,495	3,941
Total Recorded Investment	38,063	19,366	21,048
Commercial [Member] | C&I [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	5,711	5,858	7,523
Total Recorded Investment	41,454	22,765	25,484
Commercial [Member] | C&I [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	3,194	1,322	0
Recorded Investment With Allowance	756	2,810	5,343
Related Allowance	1,541	1,363	3,582
Commercial [Member] | C&I [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	4,170	4,495	3,941
Total Recorded Investment	37,504	18,633	20,141
Commercial [Member] | Municipal [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	0
Total Recorded Investment	559	733	907
Commercial [Member] | Municipal [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	0
Recorded Investment With Allowance	0
Related Allowance	0
Commercial [Member] | Municipal [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	0
Total Recorded Investment	559	733	907
Commercial [Member] | Farm [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance		937
Agriculture [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	2,730	750	571
Total Recorded Investment	6,087	1,459	1,073
Agriculture [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	1,330	57	0
Recorded Investment With Allowance	713	98	161
Related Allowance	849	50	86
Agriculture [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	1,881	700	485
Total Recorded Investment	4,044	1,304	912
Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	10,502	10,901	8,746
Total Recorded Investment	149,567	147,768	127,230
Real Estate [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	19,366	11,247	11,867
Recorded Investment With Allowance	9,984	17,494	6,320
Related Allowance	2,838	2,377	765
Real Estate [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	7,664	8,524	7,981
Total Recorded Investment	120,217	119,027	109,043
Real Estate [Member] | Construction & Development [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	2,243	2,401	2,397
Total Recorded Investment	30,929	23,989	19,586
Real Estate [Member] | Construction & Development [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	1,073	758	397
Recorded Investment With Allowance	903	686	376
Related Allowance	189	148	57
Real Estate [Member] | Construction & Development [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	2,054	2,253	2,340
Total Recorded Investment	28,953	22,545	18,813
Real Estate [Member] | Farm [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	758	994	0
Total Recorded Investment	6,533	6,166	1,684
Real Estate [Member] | Farm [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	4,597	0	452
Recorded Investment With Allowance	0	4,804	0
Related Allowance	727		0
Real Estate [Member] | Farm [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	31	57	0
Total Recorded Investment	1,936	1,362	1,232
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	3,007	3,684	2,081
Total Recorded Investment	31,655	37,139	31,464
Real Estate [Member] | Non-Owner Occupied CRE [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	7,393	1,919	2,136
Recorded Investment With Allowance	1,850	6,103	771
Related Allowance	1,235	700	152
Real Estate [Member] | Non-Owner Occupied CRE [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	1,772	2,984	1,929
Total Recorded Investment	22,412	29,117	28,557
Real Estate [Member] | Owner Occupied CRE [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	2,238	1,663	2,605
Total Recorded Investment	41,179	42,568	38,801
Real Estate [Member] | Owner Occupied CRE [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	2,892	4,661	4,111
Recorded Investment With Allowance	2,827	2,161	2,712
Related Allowance	445	232	297
Real Estate [Member] | Owner Occupied CRE [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	1,793	1,431	2,308
Total Recorded Investment	35,460	35,746	31,978
Real Estate [Member] | Residential [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	2,256	2,159	1,663
Total Recorded Investment	39,271	37,906	35,695
Real Estate [Member] | Residential [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	3,411	3,909	4,771
Recorded Investment With Allowance	4,404	3,740	2,461
Related Allowance	242	360	259
Real Estate [Member] | Residential [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	2,014	1,799	1,404
Total Recorded Investment	31,456	30,257	28,463
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	134	64	5
Total Recorded Investment	3,920	3,488	2,362
Consumer [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	814
Recorded Investment With Allowance	0	581	480
Related Allowance	73	1	1
Consumer [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	61	63	4
Total Recorded Investment	3,106	2,907	1,882
Consumer [Member] | Auto [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	5	4	3
Total Recorded Investment	2,828	2,589	1,648
Consumer [Member] | Auto [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	486
Recorded Investment With Allowance	0	464	398
Related Allowance	1	1	1
Consumer [Member] | Auto [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	4	3	2
Total Recorded Investment	2,342	2,125	1,250
Consumer [Member] | Non-Auto [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	129	60	2
Total Recorded Investment	1,092	899	714
Consumer [Member] | Non-Auto [Member] | Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance	328
Recorded Investment With Allowance	0	117	82
Related Allowance	72
Consumer [Member] | Non-Auto [Member] | Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Related Allowance	57	60	2
Total Recorded Investment	$ 764	$ 782	$ 632