Loan 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	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	$ 161,185	$ 197,451
Loans collectively evaluated for credit losses	5,227,787	4,973,582
Total Loans	5,388,972	5,171,033
Agricultural [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	5,398	6,648
Loans collectively evaluated for credit losses	92,691	88,216
Total Loans	98,089	94,864
Commercial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	1,014,980	1,312,707
Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	3,746,519	3,319,265
Consumer [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	529,384	444,197
C&I [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	24,391	30,644
Loans collectively evaluated for credit losses	812,684	1,100,738
Total Loans	837,075	1,131,382
C&I [Member] | Commercial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	837,075	1,131,382
Muncipal [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	109	9,439
Loans collectively evaluated for credit losses	177,796	171,886
Total Loans	177,905	181,325
Muncipal [Member] | Commercial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	177,905	181,325
Construction & Development [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	5,473	15,205
Loans collectively evaluated for credit losses	744,320	538,754
Total Loans	749,793	553,959
Construction & Development [Member] | Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	749,793	553,959
Farm [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	3,142	10,648
Loans collectively evaluated for credit losses	214,078	141,589
Total Loans	217,220	152,237
Farm [Member] | Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	217,220	152,237
Non - Owner Occupied CRE [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	34,468	22,626
Loans collectively evaluated for credit losses	588,966	595,060
Total Loans	623,434	617,686
Non - Owner Occupied CRE [Member] | Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	623,434	617,686
Owner Occupied CRE [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	48,504	62,730
Loans collectively evaluated for credit losses	773,149	684,244
Total Loans	821,653	746,974
Owner Occupied CRE [Member] | Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	821,653	746,974
Residential [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	37,570	37,047
Loans collectively evaluated for credit losses	1,296,849	1,211,362
Total Loans	1,334,419	1,248,409
Residential [Member] | Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	1,334,419	1,248,409
Auto [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	1,675	1,930
Loans collectively evaluated for credit losses	403,741	351,665
Total Loans	405,416	353,595
Auto [Member] | Consumer [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	405,416	353,595
Non - Auto [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Loans individually evaluated for credit losses	455	534
Loans collectively evaluated for credit losses	123,513	90,068
Total Loans	123,968	90,602
Non - Auto [Member] | Consumer [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total Loans	$ 123,968	$ 90,602