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Loans and Allowance for Credit Losses - Amortized cost basis of loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | $ 81,993 |  | $ 596,068
2023/2022 | 584,389 |  | 667,908
2022/2021 | 667,826 |  | 452,797
2021/2020 | 440,307 |  | 341,964
2020/2019 | 332,543 |  | 191,673
Prior | 452,070 |  | 273,542
Loans amortized cost basis | 240,347 |  | 235,631
Loans | 2,799,475 |  | 2,759,583
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, 2024/2023 |  |  | 43
Current period gross charge-off, 2023/2022 |  |  | 2
Current period gross charge-off, 2022/2021 | 3 |  | 58
Current period gross charge-off, 2021/2020 |  |  | 42
Current period gross charge-off, 2020/2019 |  |  | 253
Current period gross charge-off, Prior | 202 |  | 215
Current period gross charge-off, Total | 205 | $ 257 | 613
Commercial |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
Loans | 1,890,609 |  | 1,849,267
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, Total | 193 | 175 |
Consumer |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
Loans | 908,866 |  | 910,316
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, Total | 12 | 82 |
Commercial and industrial | Commercial |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 41,962 |  | 197,997
2023/2022 | 184,563 |  | 93,934
2022/2021 | 87,940 |  | 67,927
2021/2020 | 66,153 |  | 70,600
2020/2019 | 65,830 |  | 34,697
Prior | 51,208 |  | 17,566
Loans amortized cost basis | 114,039 |  | 115,600
Loans | 611,695 |  | 598,321
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, 2024/2023 |  |  | 39
Current period gross charge-off, 2022/2021 |  |  | 49
Current period gross charge-off, 2021/2020 |  |  | 11
Current period gross charge-off, 2020/2019 |  |  | 247
Current period gross charge-off, Prior | 164 |  | 90
Current period gross charge-off, Total | 164 | 175 | 436
Commercial and industrial | Commercial | Pass |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 41,962 |  | 197,533
2023/2022 | 183,564 |  | 89,090
2022/2021 | 82,980 |  | 67,691
2021/2020 | 56,800 |  | 64,272
2020/2019 | 60,343 |  | 34,603
Prior | 48,218 |  | 15,053
Loans amortized cost basis | 95,175 |  | 100,239
Loans | 569,042 |  | 568,481
Commercial and industrial | Commercial | Special Mention |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2023/2022 | 553 |  |
2021/2020 | 7,810 |  |
Prior | 14 |  |
Loans amortized cost basis | 1,878 |  |
Loans | 10,255 |  |
Commercial and industrial | Commercial | Substandard |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 |  |  | 464
2023/2022 | 446 |  | 4,844
2022/2021 | 4,960 |  | 236
2021/2020 | 1,543 |  | 6,328
2020/2019 | 5,487 |  | 94
Prior | 2,976 |  | 2,513
Loans amortized cost basis | 16,986 |  | 15,361
Loans | 32,398 |  | 29,840
Real estate construction | Commercial |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 1,851 |  | 29,902
2023/2022 | 26,751 |  | 78,611
2022/2021 | 91,181 |  | 14,326
2021/2020 | 5,154 |  | 122
2020/2019 | 100 |  |
Prior | 929 |  | 952
Loans amortized cost basis |  |  | 121
Loans | 125,966 |  | 124,034
Real estate construction | Commercial | Pass |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 1,851 |  | 29,902
2023/2022 | 26,751 |  | 57,944
2022/2021 | 70,126 |  | 14,326
2021/2020 | 5,154 |  | 122
2020/2019 | 100 |  |
Prior | 929 |  | 952
Loans amortized cost basis |  |  | 121
Loans | 104,911 |  | 103,367
Real estate construction | Commercial | Substandard |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2023/2022 |  |  | 20,667
2022/2021 | 21,055 |  |
Loans | 21,055 |  | 20,667
Residential | Real estate first mortgage | Consumer |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 5,538 |  | 72,180
2023/2022 | 71,933 |  | 207,177
2022/2021 | 203,472 |  | 218,719
2021/2020 | 216,781 |  | 108,100
2020/2019 | 106,574 |  | 33,102
Prior | 117,102 |  | 87,317
Loans amortized cost basis | 751 |  | 284
Loans | 722,151 |  | 726,879
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, 2022/2021 |  |  | 9
Current period gross charge-off, Prior |  |  | 40
Current period gross charge-off, Total |  |  | 49
Residential | Real estate first mortgage | Consumer | Performing |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 5,538 |  | 72,180
2023/2022 | 71,933 |  | 207,177
2022/2021 | 199,111 |  | 218,719
2021/2020 | 216,774 |  | 108,100
2020/2019 | 106,562 |  | 33,102
Prior | 116,181 |  | 87,212
Loans amortized cost basis | 751 |  | 284
Loans | 716,850 |  | 726,774
Residential | Real estate first mortgage | Consumer | Nonperforming |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2022/2021 | 4,361 |  |
2021/2020 | 7 |  |
2020/2019 | 12 |  |
Prior | 921 |  | 105
Loans | 5,301 |  | 105
Residential | Real estate junior lien | Consumer |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 2,303 |  | 18,408
2023/2022 | 17,642 |  | 15,655
2022/2021 | 15,169 |  | 5,946
2021/2020 | 5,983 |  | 4,857
2020/2019 | 4,528 |  | 1,769
Prior | 6,711 |  | 5,280
Loans amortized cost basis | 104,546 |  | 102,219
Loans | 156,882 |  | 154,134
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, Prior |  |  | 77
Current period gross charge-off, Total |  | 77 | 77
Residential | Real estate junior lien | Consumer | Performing |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 2,059 |  | 18,408
2023/2022 | 17,642 |  | 15,655
2022/2021 | 15,169 |  | 5,946
2021/2020 | 5,872 |  | 4,857
2020/2019 | 4,528 |  | 1,769
Prior | 6,394 |  | 5,280
Loans amortized cost basis | 102,630 |  | 100,438
Loans | 154,294 |  | 152,353
Residential | Real estate junior lien | Consumer | Nonperforming |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 244 |  |
2021/2020 | 111 |  |
Prior | 317 |  |
Loans amortized cost basis | 1,916 |  | 1,781
Loans | 2,588 |  | 1,781
Commercial real estate | Commercial |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 29,459 |  | 272,261
2023/2022 | 278,867 |  | 266,136
2022/2021 | 264,278 |  | 144,899
2021/2020 | 145,408 |  | 153,796
2020/2019 | 152,062 |  | 120,551
Prior | 274,372 |  | 161,475
Loans amortized cost basis | 8,502 |  | 7,794
Loans | 1,152,948 |  | 1,126,912
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, Prior | 29 |  |
Current period gross charge-off, Total | 29 |  |
Commercial real estate | Commercial | Pass |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 29,459 |  | 272,261
2023/2022 | 272,847 |  | 265,549
2022/2021 | 262,017 |  | 142,027
2021/2020 | 140,221 |  | 153,796
2020/2019 | 139,105 |  | 116,861
Prior | 267,003 |  | 159,454
Loans amortized cost basis | 7,854 |  | 7,794
Loans | 1,118,506 |  | 1,117,742
Commercial real estate | Commercial | Special Mention |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2020/2019 | 12,957 |  |
Prior | 1,972 |  | 262
Loans | 14,929 |  | 262
Commercial real estate | Commercial | Substandard |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2023/2022 | 6,020 |  | 587
2022/2021 | 2,261 |  | 2,872
2021/2020 | 5,187 |  |
2020/2019 |  |  | 3,690
Prior | 5,397 |  | 1,759
Loans amortized cost basis | 648 |  |
Loans | 19,513 |  | 8,908
Other revolving and installment | Consumer |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 880 |  | 5,320
2023/2022 | 4,633 |  | 6,395
2022/2021 | 5,786 |  | 980
2021/2020 | 828 |  | 4,489
2020/2019 | 3,449 |  | 1,554
Prior | 1,748 |  | 952
Loans amortized cost basis | 12,509 |  | 9,613
Loans | 29,833 |  | 29,303
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Write-off, by Origination Year [Abstract] |  |  |
Current period gross charge-off, 2024/2023 |  |  | 4
Current period gross charge-off, 2023/2022 |  |  | 2
Current period gross charge-off, 2022/2021 | 3 |  |
Current period gross charge-off, 2021/2020 |  |  | 31
Current period gross charge-off, 2020/2019 |  |  | 6
Current period gross charge-off, Prior | 9 |  | 8
Current period gross charge-off, Total | 12 | $ 5 | 51
Other revolving and installment | Consumer | Performing |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
2024/2023 | 880 |  | 5,320
2023/2022 | 4,633 |  | 6,395
2022/2021 | 5,786 |  | 980
2021/2020 | 828 |  | 4,489
2020/2019 | 3,449 |  | 1,554
Prior | 1,747 |  | 952
Loans amortized cost basis | 12,509 |  | 9,613
Loans | 29,832 |  | $ 29,303
Other revolving and installment | Consumer | Nonperforming |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] |  |  |
Prior | 1 |  |
Loans | $ 1 |  |

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