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Allowance for Credit Losses - Credit risk profile of loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023 | Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Nonperforming loans past due |  |  | 90 days |  |
Current year | $ 158,376 |  | $ 158,376 |  | $ 255,765
Prior year | 244,258 |  | 244,258 |  | 458,326
Two years before current year | 454,903 |  | 454,903 |  | 361,138
Three years before current year | 338,585 |  | 338,585 |  | 210,908
Four years before current year | 191,404 |  | 191,404 |  | 98,537
Prior | 476,704 |  | 476,704 |  | 446,015
Revolving Loans | 154,186 |  | 154,186 |  | 177,744
Total loans | 2,018,416 |  | 2,018,416 |  | 2,008,433
Current period gross charge offs, Total | 6,091 | $ 3,543 | 9,283 | $ 7,919 |
Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 176,067 |  | 176,067 |  | 348,183
Prior year | 305,584 |  | 305,584 |  | 317,948
Two years before current year | 270,809 |  | 270,809 |  | 151,284
Three years before current year | 127,292 |  | 127,292 |  | 91,864
Four years before current year | 74,246 |  | 74,246 |  | 33,181
Prior | 146,021 |  | 146,021 |  | 131,427
Revolving Loans | 73,274 |  | 73,274 |  | 72,484
Total loans | 1,173,293 |  | 1,173,293 |  | 1,146,371
Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 4 |  | 4 |  | 232
Prior year | 574 |  | 574 |  | 1,189
Two years before current year | 1,005 |  | 1,005 |  | 756
Three years before current year | 859 |  | 859 |  | 757
Four years before current year | 583 |  | 583 |  | 598
Prior | 1,974 |  | 1,974 |  | 1,735
Revolving Loans | 112 |  | 112 |  | 1
Total loans | 5,111 |  | 5,111 |  | 5,268
Total other loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 176,071 |  | 176,071 |  | 348,415
Prior year | 306,158 |  | 306,158 |  | 319,137
Two years before current year | 271,814 |  | 271,814 |  | 152,040
Three years before current year | 128,151 |  | 128,151 |  | 92,621
Four years before current year | 74,829 |  | 74,829 |  | 33,779
Prior | 147,995 |  | 147,995 |  | 133,162
Revolving Loans | 73,386 |  | 73,386 |  | 72,485
Total loans | 1,178,404 |  | 1,178,404 |  | 1,151,639
Residential | First Liens |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 24,841 |  | 24,841 |  | 49,146
Prior year | 47,700 |  | 47,700 |  | 71,073
Two years before current year | 68,600 |  | 68,600 |  | 65,232
Three years before current year | 62,265 |  | 62,265 |  | 36,816
Four years before current year | 34,456 |  | 34,456 |  | 15,242
Prior | 125,282 |  | 125,282 |  | 119,591
Revolving Loans | 671 |  | 671 |  | 1,066
Total loans | 363,815 |  | 363,815 |  | 358,166
Current period gross charge offs, Prior |  |  | 14 |  | 167
Current period gross charge offs, Total |  |  | 14 |  | 167
Residential | First Liens | Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 24,841 |  | 24,841 |  | 49,146
Prior year | 47,700 |  | 47,700 |  | 70,952
Two years before current year | 68,600 |  | 68,600 |  | 65,232
Three years before current year | 61,857 |  | 61,857 |  | 36,751
Four years before current year | 34,392 |  | 34,392 |  | 15,185
Prior | 124,100 |  | 124,100 |  | 118,087
Revolving Loans | 671 |  | 671 |  | 1,066
Total loans | 362,161 |  | 362,161 |  | 356,419
Residential | First Liens | Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Prior year |  |  |  |  | 121
Three years before current year | 408 |  | 408 |  | 65
Four years before current year | 64 |  | 64 |  | 57
Prior | 1,182 |  | 1,182 |  | 1,504
Total loans | 1,654 |  | 1,654 |  | 1,747
Residential | Home Equity |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 174 |  | 174 |  | 61
Prior year | 124 |  | 124 |  | 90
Two years before current year | 129 |  | 129 |  |
Three years before current year | 29 |  | 29 |  | 24
Four years before current year | 106 |  | 106 |  | 378
Prior | 1,416 |  | 1,416 |  | 926
Revolving Loans | 65,534 |  | 65,534 |  | 64,102
Total loans | 67,512 |  | 67,512 |  | 65,581
Current period gross charge offs, 2022 |  |  | 22 |  |
Current period gross charge offs, Revolving Loans |  |  | 20 |  |
Current period gross charge offs, Total |  |  | 42 |  |
Residential | Home Equity | Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 174 |  | 174 |  | 61
Prior year | 124 |  | 124 |  | 68
Two years before current year | 54 |  | 54 |  |
Three years before current year | 29 |  | 29 |  | 7
Four years before current year | 90 |  | 90 |  | 378
Prior | 1,333 |  | 1,333 |  | 866
Revolving Loans | 65,461 |  | 65,461 |  | 64,102
Total loans | 67,265 |  | 67,265 |  | 65,482
Residential | Home Equity | Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Prior year |  |  |  |  | 22
Two years before current year | 75 |  | 75 |  |
Three years before current year |  |  |  |  | 17
Four years before current year | 16 |  | 16 |  |
Prior | 83 |  | 83 |  | 60
Revolving Loans | 73 |  | 73 |  |
Total loans | 247 |  | 247 |  | 99
Residential | Junior Liens |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 6,875 |  | 6,875 |  | 15,050
Prior year | 13,795 |  | 13,795 |  | 15,484
Two years before current year | 13,889 |  | 13,889 |  | 8,293
Three years before current year | 7,245 |  | 7,245 |  | 5,661
Four years before current year | 5,589 |  | 5,589 |  | 4,280
Prior | 10,698 |  | 10,698 |  | 8,197
Revolving Loans | 1,501 |  | 1,501 |  | 1,698
Total loans | 59,592 |  | 59,592 |  | 58,663
Current period gross charge offs, 2020 |  |  |  |  | 24
Current period gross charge offs, Prior |  |  |  |  | 24
Current period gross charge offs, Total |  |  |  |  | 48
Residential | Junior Liens | Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 6,875 |  | 6,875 |  | 15,050
Prior year | 13,693 |  | 13,693 |  | 15,431
Two years before current year | 13,889 |  | 13,889 |  | 8,248
Three years before current year | 7,245 |  | 7,245 |  | 5,557
Four years before current year | 5,525 |  | 5,525 |  | 4,280
Prior | 10,532 |  | 10,532 |  | 8,094
Revolving Loans | 1,501 |  | 1,501 |  | 1,698
Total loans | 59,260 |  | 59,260 |  | 58,358
Residential | Junior Liens | Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Prior year | 102 |  | 102 |  | 53
Two years before current year |  |  |  |  | 45
Three years before current year |  |  |  |  | 104
Four years before current year | 64 |  | 64 |  |
Prior | 166 |  | 166 |  | 103
Total loans | 332 |  | 332 |  | 305
Residential | All Other Residential |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 498 |  | 498 |  | 6,432
Prior year | 7,385 |  | 7,385 |  | 9,477
Two years before current year | 7,717 |  | 7,717 |  | 3,146
Three years before current year | 2,703 |  | 2,703 |  | 421
Four years before current year | 398 |  | 398 |  | 1,031
Prior | 2,419 |  | 2,419 |  | 1,549
Revolving Loans | 234 |  | 234 |  | 415
Total loans | 21,354 |  | 21,354 |  | 22,471
Current period gross charge offs, Prior |  |  |  |  | 1
Current period gross charge offs, Total |  |  |  |  | 1
Residential | All Other Residential | Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 498 |  | 498 |  | 6,432
Prior year | 7,385 |  | 7,385 |  | 9,477
Two years before current year | 7,717 |  | 7,717 |  | 3,100
Three years before current year | 2,703 |  | 2,703 |  | 421
Four years before current year | 398 |  | 398 |  | 641
Prior | 1,994 |  | 1,994 |  | 1,511
Revolving Loans | 234 |  | 234 |  | 415
Total loans | 20,929 |  | 20,929 |  | 21,997
Residential | All Other Residential | Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Two years before current year |  |  |  |  | 46
Four years before current year |  |  |  |  | 390
Prior | 425 |  | 425 |  | 38
Total loans | 425 |  | 425 |  | 474
Consumer | Motor Vehicle |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 137,535 |  | 137,535 |  | 265,165
Prior year | 228,071 |  | 228,071 |  | 216,098
Two years before current year | 176,621 |  | 176,621 |  | 71,446
Three years before current year | 53,078 |  | 53,078 |  | 47,471
Four years before current year | 32,574 |  | 32,574 |  | 12,172
Prior | 7,351 |  | 7,351 |  | 2,207
Revolving Loans | 12 |  | 12 |  |
Total loans | 635,242 |  | 635,242 |  | 614,559
Current period gross charge offs, 2024 |  |  | 49 |  | 841
Current period gross charge offs, 2023 |  |  | 1,369 |  | 7,722
Current period gross charge offs, 2022 |  |  | 2,408 |  | 3,101
Current period gross charge offs, 2021 |  |  | 987 |  | 1,448
Current period gross charge offs, 2020 |  |  | 354 |  | 499
Current period gross charge offs, Prior |  |  | 57 |  | 174
Current period gross charge offs, Total |  |  | 5,224 |  | 13,785
Consumer | Motor Vehicle | Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 137,531 |  | 137,531 |  | 264,933
Prior year | 227,663 |  | 227,663 |  | 215,125
Two years before current year | 175,727 |  | 175,727 |  | 70,926
Three years before current year | 52,729 |  | 52,729 |  | 46,939
Four years before current year | 32,161 |  | 32,161 |  | 12,038
Prior | 7,238 |  | 7,238 |  | 2,177
Revolving Loans | 12 |  | 12 |  |
Total loans | 633,061 |  | 633,061 |  | 612,138
Consumer | Motor Vehicle | Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 4 |  | 4 |  | 232
Prior year | 408 |  | 408 |  | 973
Two years before current year | 894 |  | 894 |  | 520
Three years before current year | 349 |  | 349 |  | 532
Four years before current year | 413 |  | 413 |  | 134
Prior | 113 |  | 113 |  | 30
Total loans | 2,181 |  | 2,181 |  | 2,421
Consumer | All Other Consumer |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 6,148 |  | 6,148 |  | 12,561
Prior year | 9,083 |  | 9,083 |  | 6,915
Two years before current year | 4,858 |  | 4,858 |  | 3,923
Three years before current year | 2,831 |  | 2,831 |  | 2,228
Four years before current year | 1,706 |  | 1,706 |  | 676
Prior | 829 |  | 829 |  | 692
Revolving Loans | 5,434 |  | 5,434 |  | 5,204
Total loans | 30,889 |  | 30,889 |  | 32,199
Current period gross charge offs, 2024 |  |  |  |  | 61
Current period gross charge offs, 2023 |  |  | 62 |  | 213
Current period gross charge offs, 2022 |  |  | 57 |  | 61
Current period gross charge offs, 2021 |  |  | 5 |  | 37
Current period gross charge offs, 2020 |  |  | 7 |  | 3
Current period gross charge offs, Prior |  |  | 9 |  | 5
Current period gross charge offs, Revolving Loans |  |  | 84 |  | 149
Current period gross charge offs, Total |  |  | 224 |  | 529
Consumer | All Other Consumer | Performing |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Current year | 6,148 |  | 6,148 |  | 12,561
Prior year | 9,019 |  | 9,019 |  | 6,895
Two years before current year | 4,822 |  | 4,822 |  | 3,778
Three years before current year | 2,729 |  | 2,729 |  | 2,189
Four years before current year | 1,680 |  | 1,680 |  | 659
Prior | 824 |  | 824 |  | 692
Revolving Loans | 5,395 |  | 5,395 |  | 5,203
Total loans | 30,617 |  | 30,617 |  | 31,977
Consumer | All Other Consumer | Nonperforming Loans |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |
Prior year | 64 |  | 64 |  | 20
Two years before current year | 36 |  | 36 |  | 145
Three years before current year | 102 |  | 102 |  | 39
Four years before current year | 26 |  | 26 |  | 17
Prior | 5 |  | 5 |  |
Revolving Loans | 39 |  | 39 |  | 1
Total loans | $ 272 |  | $ 272 |  | $ 222

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