Loans and Allowance for Credit Losses - Schedule of Allowance for Credit Losses on Off-Balance Sheet Credit Exposures (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	$ 48,238	$ 47,590	$ 48,365	$ 51,834	$ 55,525	$ 33,709
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	1,518		2,223
Commercial Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	22,665	21,764	22,478	15,225	15,118	9,012
Commercial Real Estate [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	402		484
Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	13,209	13,814	12,248	18,690	19,965	12,456
Commercial and Industrial [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	742		1,323
Residential Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	6,818	5,960	5,560	9,808	11,511	4,559
Residential Real Estate [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	49		16
Agricultural [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	2,289	2,472	3,756	4,695	4,349	758
Agricultural [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	4		3
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	2,250	$ 2,038	2,088	$ 2,569	$ 2,682	$ 6,020
Consumer [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, allowance for credit losses	$ 321		$ 397