Loans - Distribution of Fixed Rate Loans and Variable Rate Loans by Major Loan Category (Detail) $ in Thousands	Jun. 30, 2022 USD ($)
Consumer Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	$ 309,221
Distribution of variable rate loans by major loan category, Variable Rate	101,229
Agricultural Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	127,103
Distribution of variable rate loans by major loan category, Variable Rate	72,869
Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	48,479
Distribution of variable rate loans by major loan category, Variable Rate	78,664
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	787,908
Distribution of variable rate loans by major loan category, Variable Rate	191,268
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	109,452
Distribution of variable rate loans by major loan category, Variable Rate	123,523
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	54,462
Distribution of variable rate loans by major loan category, Variable Rate	949
Other Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Distribution of fixed rate loans by major loan category, Fixed Rate	21,341
Distribution of variable rate loans by major loan category, Variable Rate	$ 9,902