Loans Held for Investment and Allowance for Loan Losses - Loans Held-for-Investment by Class of Financing Receivables (Detail) - USD ($) $ in Thousands		Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		$ 6,777,570		$ 6,441,868	$ 5,878,582
Total Real Estate		28,672		24,325	25,495
Less: Allowance for credit losses		(86,541)	$ 0	(75,834)	(71,932)	$ (66,913)	$ (63,465)
Net loans held for investment		6,691,029		6,366,034	5,806,650
C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,021,863		917,317	839,928
Less: Allowance for credit losses		(16,530)	(16,083)	(16,129)	(18,589)	(15,737)	(12,280)
Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		215,977		221,090	200,577
Less: Allowance for credit losses		(187)	(1,067)	(1,026)	(1,352)	(1,418)	(348)
Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		915,221		959,426	928,644
Less: Allowance for credit losses		(28,966)	(28,627)	(26,443)	(21,085)	(17,887)	(17,627)
Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		335,644		306,322	250,028
Less: Allowance for credit losses		(2,804)	(1,937)	(1,957)	(1,006)	(873)	(663)
Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		811,347		732,089	636,432
Less: Allowance for credit losses		(13,471)	(9,051)	(9,075)	(8,410)	(8,499)	(10,722)
Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,011,511		954,400	909,899
Less: Allowance for credit losses		(12,572)	(11,948)	(9,928)	(10,740)	(11,536)	(10,828)
Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,698,679		1,575,758	1,412,125
Less: Allowance for credit losses		(9,767)	(9,702)	(9,075)	(8,304)	(7,829)	(8,133)
Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		534,603		550,635	468,147
Less: Allowance for credit losses		(829)	(857)	(845)	(912)	(869)	(896)
Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		150,693		147,884	142,382
Less: Allowance for credit losses		(333)	(332)	(315)	(372)	(354)	(371)
Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,237,840		1,138,407	1,040,505
Commercial [Member] | C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	[1]	1,021,863		917,317	839,928
Commercial [Member] | Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		215,977		221,090	200,577
Agriculture [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		82,032		76,947	90,420
Less: Allowance for credit losses		(1,082)	$ (1,214)	(1,041)	(1,162)	$ (1,911)	$ (1,597)
Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		4,772,402		4,527,995	4,137,128
Real Estate [Member] | Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		915,221		959,426	928,644
Real Estate [Member] | Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		335,644		306,322	250,028
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		811,347		732,089	636,432
Real Estate [Member] | Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,011,511		954,400	909,899
Real Estate [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,698,679		1,575,758	1,412,125
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		685,296		698,519	610,529
Consumer [Member] | Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		534,603		550,635	468,147
Consumer [Member] | Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		$ 150,693		$ 147,884	$ 142,382

[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.