v3.26.1
Servicing - Additional Information (Detail)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2026
USD ($)
Loan
Strata
Jun. 30, 2025
USD ($)
Loan
Strata
Dec. 31, 2025
USD ($)
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
Valuation allowance $ 1,300   $ 883
1-4 Family Real Estate Loans [Member]      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
Loans serviced for others unpaid principal amount 365,500 $ 362,800 362,600
Capitalized service right assets included in other assets 3,800 3,500 3,600
Fair value of the capitalized servicing rights $ 4,300 $ 4,700 $ 4,500
Number of loans | Loan 3,573 3,629  
Number of strata which included loan | Strata 2 2  
Prepayment rate 11.70% 7.70% 9.80%
Discount yield 5.77% 5.52%  
Valuation allowance $ 5 $ 3 $ 5
Agricultural Real Estate Loans [Member]      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
Loans serviced for others unpaid principal amount 168,200 146,800 153,400
Capitalized service right assets included in other assets 2,600 2,300 2,400
Fair value of the capitalized servicing rights $ 1,300 $ 2,300 $ 1,500
Number of loans | Loan 666 643  
Number of strata which included loan | Strata 14 12  
Prepayment rate 1.536% 0.447% 1.054%
Fair value of impairment expense $ 396    
Discount yield 7.84% 8.37%  
Valuation allowance $ 1,300 $ 84  
Two 1-4 Family Real Estate Strata [Member]      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
Number of loans | Loan 67 77  
Twelve Agricultural Real Estate Strata [Member]      
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items]      
Number of loans | Loan   147