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Loans - Analysis of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | $ 19,591 | $ 21,575 | $ 17,283 | $ 17,283
Charge Offs | $ (148) | (123) | (330) | (334) | (827)
Recoveries | 55 | 52 | 310 | 237 | 298
Provision for credit losses-loans | 460 | 1,637 | 1,420 | 3,845 | 4,600
Provision for credit losses-off balance sheet credit exposures | (76) |  | (143) |  |
Other Non-interest expense related to unfunded |  | (49) |  | 77 | 221
Balance at ending of year |  | 21,108 |  | 21,108 | 21,575
Ending balance: individually evaluated for impairment |  | 2,436 |  | 2,436 | 1,996
Ending balance: collectively evaluated for impairment |  | 18,672 |  | 18,672 | 19,579
Ending balance: loans acquired with deteriorated credit quality |  |  |  |  | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 2,529,606 | 2,142,616 | $ 2,529,606 | 2,142,616 | 2,356,387
Ending balance: individually evaluated for impairment |  | 10,753 |  | 10,753 | 8,857
Ending balance: collectively evaluated for impairment |  | 2,131,131 |  | 2,131,131 | 2,346,871
Ending balance: loans acquired with deteriorated credit quality |  | 732 |  | 732 | 659
Cumulative Effect, Period of Adoption, Adjustment [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Accounting Standards Update [Extensible Enumeration] |  |  | Accounting Standards Update 2016-13 [Member] |  |
Consumer Real Estate [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 939 | $ 998 | 857 | 857
Recoveries | 14 | 6 | 27 | 15 | 20
Provision for credit losses-loans | (170) | 19 | (57) | 54 | 121
Balance at ending of year |  | 926 |  | 926 | 998
Ending balance: individually evaluated for impairment |  |  |  |  | 6
Ending balance: collectively evaluated for impairment |  | 926 |  | 926 | 992
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 512,990 | 416,044 | 512,990 | 416,044 | 494,423
Ending balance: individually evaluated for impairment |  | 624 |  | 624 | 569
Ending balance: collectively evaluated for impairment |  | 414,951 |  | 414,951 | 493,449
Ending balance: loans acquired with deteriorated credit quality |  | 469 |  | 469 | 405
Agricultural Real Estate [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 346 | 349 | 1,040 | 1,040
Recoveries | 1 |  | 105 |  |
Provision for credit losses-loans | 77 | (10) | 27 | (684) | (691)
Balance at ending of year |  | 356 |  | 356 | 349
Ending balance: individually evaluated for impairment |  |  |  |  | 0
Ending balance: collectively evaluated for impairment |  | 356 |  | 356 | 349
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 225,370 | 204,787 | 225,370 | 204,787 | 220,514
Ending balance: individually evaluated for impairment |  | 2,588 |  | 2,588 | 2,280
Ending balance: collectively evaluated for impairment |  | 202,003 |  | 202,003 | 218,039
Ending balance: loans acquired with deteriorated credit quality |  | 196 |  | 196 | 195
Agricultural [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 754 | 751 | 709 | 709
Recoveries |  | 1 |  | 1 | 7
Provision for credit losses-loans | 78 | (1) | 84 | 46 | 35
Balance at ending of year |  | 756 |  | 756 | 751
Ending balance: individually evaluated for impairment |  |  |  |  | 0
Ending balance: collectively evaluated for impairment |  | 756 |  | 756 | 751
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 123,971 | 128,818 | 123,971 | 128,818 | 128,926
Ending balance: individually evaluated for impairment |  | 1,334 |  | 1,334 | 152
Ending balance: collectively evaluated for impairment |  | 127,484 |  | 127,484 | 128,774
Commercial Real Estate [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 10,427 | 11,924 | 9,130 | 9,130
Recoveries | 1 | 2 | 6 | 7 | 9
Provision for credit losses-loans | 123 | (1,122) | 1,374 | 2,414 | 2,785
Balance at ending of year |  | 11,551 |  | 11,551 | 11,924
Ending balance: individually evaluated for impairment |  | 500 |  | 500 | 438
Ending balance: collectively evaluated for impairment |  | 11,051 |  | 11,051 | 11,486
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 1,301,614 | 1,061,904 | 1,301,614 | 1,061,904 | 1,150,511
Ending balance: individually evaluated for impairment |  | 4,187 |  | 4,187 | 4,108
Ending balance: collectively evaluated for impairment |  | 1,057,699 |  | 1,057,699 | 1,146,389
Ending balance: loans acquired with deteriorated credit quality |  | 18 |  | 18 | 14
Commercial and Industrial [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 5,365 | 5,382 | 3,847 | 3,847
Charge Offs |  |  |  | (6) | (418)
Recoveries | 6 | 8 | 18 | 82 | 93
Provision for credit losses-loans | (65) | 297 | (527) | 1,747 | 1,860
Balance at ending of year |  | 5,670 |  | 5,670 | 5,382
Ending balance: individually evaluated for impairment |  | 1,936 |  | 1,936 | 1,551
Ending balance: collectively evaluated for impairment |  | 3,734 |  | 3,734 | 3,831
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 281,839 | 260,000 | 281,839 | 260,000 | 272,119
Ending balance: individually evaluated for impairment |  | 2,003 |  | 2,003 | 1,581
Ending balance: collectively evaluated for impairment |  | 257,948 |  | 257,948 | 270,493
Ending balance: loans acquired with deteriorated credit quality |  | 49 |  | 49 | 45
Consumer [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 567 | 891 | 625 | 625
Charge Offs | (148) | (123) | (330) | (328) | (409)
Recoveries | 33 | 35 | 154 | 132 | 169
Provision for credit losses-loans | 417 | 246 | 519 | 296 | 506
Balance at ending of year |  | 725 |  | 725 | 891
Ending balance: individually evaluated for impairment |  |  |  |  | 1
Ending balance: collectively evaluated for impairment |  | 725 |  | 725 | 890
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
FINANCING RECEIVABLES: |  |  |  |  |
Ending balance | 83,822 | 71,063 | 83,822 | 71,063 | 89,894
Ending balance: individually evaluated for impairment |  | 17 |  | 17 | 167
Ending balance: collectively evaluated for impairment |  | 71,046 |  | 71,046 | 89,727
Unallocated [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  | 26 | 18 | 34 | 34
Provision for credit losses-loans |  | 20 |  | (28) | (16)
Balance at ending of year |  | 6 |  | 6 | 18
Ending balance: collectively evaluated for impairment |  | 6 |  | 6 | 18
Ending balance: loans acquired with deteriorated credit quality |  | 0 |  | 0 | 0
Unfunded Loan Commitment & Letters of Credit [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year | 2,099 | 1,167 | 1,262 | 1,041 | 1,041
Provision for credit losses-off balance sheet credit exposures | (76) |  | (143) |  |
Other Non-interest expense related to unfunded |  | (49) |  | 77 | 221
Balance at ending of year | $ 2,023 | 1,118 | 2,023 | 1,118 | 1,262
Ending balance: collectively evaluated for impairment |  | 1,118 |  | 1,118 | 1,262
Ending balance: loans acquired with deteriorated credit quality |  | $ 0 |  | $ 0 | 0
Unfunded Loan Commitment & Letters of Credit [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] |  |  |  |  |
ALLOWANCE FOR CREDIT LOSSES: |  |  |  |  |
Balance at beginning of year |  |  | $ 904 |  |
Balance at ending of year |  |  |  |  | $ 904

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