v3.25.2
Loans - Amortized Cost of Nonaccrual Loans by Portfolio Segment (Detail) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Nonaccrual With No Allowance For Credit Loss [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans $ 3,252 $ 2,392
Nonaccrual With No Allowance For Credit Loss [Member] | Consumer Real Estate [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 2,556 1,637
Nonaccrual With No Allowance For Credit Loss [Member] | Agricultural Real Estate [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 461 130
Nonaccrual With No Allowance For Credit Loss [Member] | Agricultural [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 60 90
Nonaccrual With No Allowance For Credit Loss [Member] | Commercial Real Estate [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 141 360
Nonaccrual With No Allowance For Credit Loss [Member] | Commercial & Industrial [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans   57
Nonaccrual With No Allowance For Credit Loss [Member] | Consumer [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 34 118
Nonaccrual [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 3,745 3,124
Nonaccrual [Member] | Consumer Real Estate [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 3,049 2,369
Nonaccrual [Member] | Agricultural Real Estate [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 461 130
Nonaccrual [Member] | Agricultural [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 60 90
Nonaccrual [Member] | Commercial Real Estate [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans 141 360
Nonaccrual [Member] | Commercial & Industrial [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans   57
Nonaccrual [Member] | Consumer [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Investment in nonaccrual loans $ 34 $ 118