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Loans - Analysis of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Charge Offs | $ (192) | $ (122) | $ (990)
Recoveries | 137 | 62 | 439
Provision for credit losses-loans | (289) | 817 | $ 1,698
Provision for credit losses-off balance sheet credit exposures | (266) | $ 62 |
Cumulative Effect, Period of Adoption, Adjustment [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Accounting Standards Update [Extensible Enumeration] |  | Accounting Standards Update 2016-13 [Member] | Accounting Standards Update 2016-13 [Member]
Consumer Real Estate [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Charge Offs | (10) |  |
Recoveries | 4 | $ 7 | $ 35
Provision for credit losses-loans | (290) | (256) | (326)
Agricultural Real Estate [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Recoveries |  |  | 105
Provision for credit losses-loans | 859 | 26 | 24
Agricultural [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Recoveries |  |  | 10
Provision for credit losses-loans | 41 | (35) | 225
Commercial Real Estate [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Recoveries | 3 | 2 | 8
Provision for credit losses-loans | (1,450) | 661 | 1,967
Commercial and Industrial [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Charge Offs | (101) |  | (565)
Recoveries | 66 | 6 | 84
Provision for credit losses-loans | 674 | 191 | (643)
Consumer [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Charge Offs | (81) | (122) | (425)
Recoveries | 64 | 47 | 197
Provision for credit losses-loans | (123) | 230 | 451
Unfunded Loan Commitment & Letters of Credit [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Balance at beginning of year | 2,212 | 1,262 | 1,262
Provision for credit losses-off balance sheet credit exposures | (266) | 62 | 46
Balance at ending of year | $ 1,946 | 2,228 | 2,212
Unfunded Loan Commitment & Letters of Credit [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |
Balance at beginning of year |  | $ 904 | $ 904

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