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Servicing - Additional Information (Detail) $ in Thousands | 12 Months Ended
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Dec. 31, 2023 USD ($) Loan Strata | Dec. 31, 2022 USD ($)
Customer Securities for which Entity has Right to Sell or Repledge (Including Securities Sold or Repledged) [Line Items] |  |
Valuation allowance | $ 7 |
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 | 367,800 | $ 375,600
Capitalized service right assets included in other assets | 3,500 | 3,500
Fair value of the capitalized servicing rights | $ 5,500 | $ 5,100
Number of loans | Loan | 3,749 |
Number of strata which included loan | Strata | 2 |
Prepayment rate | 6.30% | 7.70%
Discount yield | 5.70% |
Valuation allowance | $ 2 |
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 | 135,800 |
Capitalized service right assets included in other assets | 2,200 |
Fair value of the capitalized servicing rights | $ 2,600 |
Number of loans | Loan | 593 |
Number of strata which included loan | Strata | 11 |
Discount yield | 8.66% | 5.94%
Valuation allowance | $ 5 |
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 | 103 |
Eleven 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 | 41 |

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- Definition Amount of increase (decrease) in the amortized amount from a decrease (increase) in the valuation allowance applied to the servicing asset for a contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 50 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a)(5) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481229/860-50-50-4 + Details
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