Loans Held for Investment and Allowance for Loan Losses - Loans Held-for-Investment by Class of Financing Receivables (Detail) - USD ($) $ in Thousands		Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		$ 5,878,582		$ 5,388,972	$ 5,304,602
Less: Allowance for credit losses		(71,932)	$ (66,913)	(63,465)	(62,138)	$ (62,974)	$ (66,534)
Net loans held for investment		5,806,650		5,325,507	5,242,464
C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		839,928		837,075	983,103
Less: Allowance for credit losses		(18,589)	(15,737)	(12,280)	(10,186)	(12,323)	(13,609)
Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		200,577		177,905	179,356
Less: Allowance for credit losses		(1,352)	(1,418)	(348)	(588)	(2,191)	(1,552)
Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		928,644		749,793	550,928
Less: Allowance for credit losses		(21,085)	(17,887)	(17,627)	(15,632)	(13,246)	(13,512)
Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		250,028		217,220	185,288
Less: Allowance for credit losses		(1,006)	(873)	(663)	(607)	(1,223)	(1,876)
Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		636,432		623,434	673,608
Less: Allowance for credit losses		(8,410)	(8,499)	(10,722)	(10,432)	(9,492)	(8,391)
Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		909,899		821,653	820,055
Less: Allowance for credit losses		(10,740)	(11,536)	(10,828)	(10,399)	(9,878)	(12,347)
Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,412,125		1,334,419	1,328,474
Less: Allowance for credit losses		(8,304)	(7,829)	(8,133)	(11,234)	(11,189)	(12,601)
Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		468,147		405,416	383,764
Less: Allowance for credit losses		(912)	(869)	(896)	(1,266)	(1,068)	(1,020)
Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		142,382		123,968	104,814
Less: Allowance for credit losses		(372)	(354)	(371)	(482)	(379)	(371)
Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,040,505		1,014,980	1,162,459
Commercial [Member] | C&I [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	[1]	839,928		837,075	983,103
Commercial [Member] | Municipal [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		200,577		177,905	179,356
Agriculture [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		90,420		98,089	95,212
Less: Allowance for credit losses		(1,162)	$ (1,911)	(1,597)	(1,312)	$ (1,985)	$ (1,255)
Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		4,137,128		3,746,519	3,558,353
Real Estate [Member] | Construction & Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		928,644		749,793	550,928
Real Estate [Member] | Farm [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		250,028		217,220	185,288
Real Estate [Member] | Non-Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		636,432		623,434	673,608
Real Estate [Member] | Owner Occupied CRE [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		909,899		821,653	820,055
Real Estate [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		1,412,125		1,334,419	1,328,474
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		610,529		529,384	488,578
Consumer [Member] | Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		468,147		405,416	383,764
Consumer [Member] | Non-Auto [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total Loans		$ 142,382		$ 123,968	$ 104,814

[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.