v3.26.1
Loans and Allowance for Credit Losses - Schedule of Allowance for Credit Losses on Off-Balance Sheet Credit Exposures (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses $ 64,413 $ 64,245 $ 52,756 $ 45,270 $ 45,824 $ 43,267
SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 2,501   1,753      
Commercial Real Estate [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 23,667 22,882 20,037 16,250 16,122 14,948
Commercial Real Estate [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 272   272      
Commercial and Industrial [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 23,325 23,850 17,830 13,237 13,548 14,005
Commercial and Industrial [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 1,841   1,409      
Agricultural Real Estate [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 7,587 7,665 4,669 5,132 5,158 3,504
Agricultural Real Estate [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 209   4      
Residential Real Estate [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 7,482 7,701 8,068 8,542 8,827 8,553
Residential Real Estate [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 96   47      
Agricultural [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 609 291 337 268 356 439
Agricultural [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 4          
Consumer [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses 1,743 $ 1,856 1,815 $ 1,841 $ 1,813 $ 1,818
Consumer [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member] | Off Balance Sheet Credit Loss Liability [Member]            
Accounts Notes And Loans Receivable [Line Items]            
Loans, allowance for credit losses $ 79   $ 21