Loans Held for Investment and Allowance for Loan Losses - Loans Held-for-Investment by Class of Financing Receivables (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022		Mar. 31, 2022		Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	$ 6,576,215	$ 6,441,868		$ 5,566,169
Total Real Estate	24,171	24,325		28,743
Less: Allowance for credit losses	(80,818)	(75,834)		(66,913)		$ (63,465)
Net loans held for investment	6,495,397	6,366,034		5,499,256
C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	954,686	917,317		838,049
Less: Allowance for credit losses	(16,083)	(16,129)		(15,737)		(12,280)
Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	221,379	221,090		191,799
Less: Allowance for credit losses	(1,067)	(1,026)		(1,418)		(348)
Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	921,190	959,426		806,211
Less: Allowance for credit losses	(28,627)	(26,443)		(17,887)		(17,627)
Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	307,706	306,322		225,942
Less: Allowance for credit losses	(1,937)	(1,957)		(873)		(663)
Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	737,117	732,089		636,160
Less: Allowance for credit losses	(9,051)	(9,075)		(8,499)		(10,722)
Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,043,018	954,400		881,181
Less: Allowance for credit losses	(11,948)	(9,928)		(11,536)		(10,828)
Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,628,841	1,575,758		1,352,162
Less: Allowance for credit losses	(9,702)	(9,075)		(7,829)		(8,133)
Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	537,410	550,635		419,818
Less: Allowance for credit losses	(857)	(845)		(869)		(896)
Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	147,851	147,884		131,964
Less: Allowance for credit losses	(332)	(315)		(354)		(371)
Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,176,065	1,138,407		1,029,848
Commercial [Member] | C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	954,686	917,317	[1]	838,049	[1]
Commercial [Member] | Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	221,379	221,090		191,799
Agriculture [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	77,017	76,947		82,883
Less: Allowance for credit losses	(1,214)	(1,041)		(1,911)		$ (1,597)
Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	4,637,872	4,527,995		3,901,656
Real Estate [Member] | Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	921,190	959,426		806,211
Real Estate [Member] | Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	307,706	306,322		225,942
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	737,117	732,089		636,160
Real Estate [Member] | Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,043,018	954,400		881,181
Real Estate [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,628,841	1,575,758		1,352,162
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	685,261	698,519		551,782
Consumer [Member] | Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	537,410	550,635		419,818
Consumer [Member] | Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	$ 147,851	$ 147,884		$ 131,964

[1] All disclosures for the C&I loan segment include PPP loan balances, net of deferred fees and costs, as disclosed on the face of the consolidated balance sheet.