v3.26.3
Allowance for Credit Losses - Credit risk profile of loans (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Dec. 31, 2025
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Financing Receivable, Credit Quality Indicator [Line Items]          
Nonperforming loans past due       90 days  
Current year $ 422,989 $ 284,945   $ 284,945  
Prior year 448,390 503,965   503,965  
Two years before current year 266,301 429,075   429,075  
Three years before current year 427,076 235,943   235,943  
Four years before current year 357,624 396,416   396,416  
Prior 552,346 772,090   772,090  
Revolving Loans 230,987 244,895   244,895  
Total loans 2,705,713 2,867,329   2,867,329  
Current period gross charge offs, Total   3,049 $ 3,226 10,078 $ 9,395
Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 380,203 324,933   324,933  
Prior year 256,443 319,957   319,957  
Two years before current year 170,253 209,949   209,949  
Three years before current year 166,830 134,899   134,899  
Four years before current year 84,682 131,924   131,924  
Prior 163,410 248,375   248,375  
Revolving Loans 117,651 162,634   162,634  
Total loans 1,339,472 1,532,671   1,532,671  
Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 224 96   96  
Prior year 670 678   678  
Two years before current year 719 1,591   1,591  
Three years before current year 943 854   854  
Four years before current year 357 665   665  
Prior 1,878 1,403   1,403  
Revolving Loans 458 105   105  
Total loans 5,249 5,392   5,392  
Total other loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 380,427 325,029   325,029  
Prior year 257,113 320,635   320,635  
Two years before current year 170,972 211,540   211,540  
Three years before current year 167,773 135,753   135,753  
Four years before current year 85,039 132,589   132,589  
Prior 165,288 249,778   249,778  
Revolving Loans 118,109 162,739   162,739  
Total loans 1,344,721 1,538,063   1,538,063  
Residential | First Liens          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 64,142 53,249   53,249  
Prior year 61,845 69,345   69,345  
Two years before current year 39,526 71,929   71,929  
Three years before current year 74,359 48,801   48,801  
Four years before current year 60,965 75,423   75,423  
Prior 145,766 225,211   225,211  
Revolving Loans 1,786 7,524   7,524  
Total loans 448,389 551,482   551,482  
Current period gross charge offs, 2024 33     9  
Current period gross charge offs, 2023 31        
Current period gross charge offs, 2021       10  
Current period gross charge offs, Prior 11     169  
Current period gross charge offs, Total 75     188  
Residential | First Liens | Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 64,142 53,249   53,249  
Prior year 61,775 69,267   69,267  
Two years before current year 39,526 71,181   71,181  
Three years before current year 74,359 48,430   48,430  
Four years before current year 60,920 75,423   75,423  
Prior 144,310 224,183   224,183  
Revolving Loans 1,786 7,524   7,524  
Total loans 446,818 549,257   549,257  
Residential | First Liens | Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Prior year 70 78   78  
Two years before current year   748   748  
Three years before current year   371   371  
Four years before current year 45        
Prior 1,456 1,028   1,028  
Total loans 1,571 2,225   2,225  
Residential | Home Equity          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 338 140   140  
Prior year 938 476   476  
Two years before current year 793 472   472  
Three years before current year 683 696   696  
Four years before current year 276 2,216   2,216  
Prior 1,459 3,054   3,054  
Revolving Loans 102,300 135,767   135,767  
Total loans 106,787 142,821   142,821  
Current period gross charge offs, 2023       21  
Current period gross charge offs, 2022 22        
Current period gross charge offs, Prior 19     43  
Current period gross charge offs, Revolving Loans 10        
Current period gross charge offs, Total 51     64  
Residential | Home Equity | Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 338 140   140  
Prior year 938 476   476  
Two years before current year 793 472   472  
Three years before current year 650 696   696  
Four years before current year 259 2,162   2,162  
Prior 1,284 2,891   2,891  
Revolving Loans 101,907 135,683   135,683  
Total loans 106,169 142,520   142,520  
Residential | Home Equity | Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Three years before current year 33        
Four years before current year 17 54   54  
Prior 175 163   163  
Revolving Loans 393 84   84  
Total loans 618 301   301  
Residential | Junior Liens          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 23,832 17,394   17,394  
Prior year 13,417 21,716   21,716  
Two years before current year 9,561 12,147   12,147  
Three years before current year 9,170 8,874   8,874  
Four years before current year 4,691 8,164   8,164  
Prior 9,775 10,980   10,980  
Revolving Loans 2,107 4,172   4,172  
Total loans 72,553 83,447   83,447  
Current period gross charge offs, 2024 30     81  
Current period gross charge offs, Prior 85     23  
Current period gross charge offs, Total 115     104  
Residential | Junior Liens | Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 23,832 17,394   17,394  
Prior year 13,403 21,688   21,688  
Two years before current year 9,409 11,936   11,936  
Three years before current year 9,145 8,737   8,737  
Four years before current year 4,674 8,089   8,089  
Prior 9,676 10,924   10,924  
Revolving Loans 2,107 4,172   4,172  
Total loans 72,246 82,940   82,940  
Residential | Junior Liens | Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Prior year 14 28   28  
Two years before current year 152 211   211  
Three years before current year 25 137   137  
Four years before current year 17 75   75  
Prior 99 56   56  
Total loans 307 507   507  
Residential | All Other Residential          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 7,829 10,132   10,132  
Prior year 6,807 11,281   11,281  
Two years before current year 3,843 4,394   4,394  
Three years before current year 4,991 2,733   2,733  
Four years before current year 3,622 3,360   3,360  
Prior 1,765 3,145   3,145  
Total loans 28,857 35,045   35,045  
Current period gross charge offs, Prior       38  
Current period gross charge offs, Total       38  
Residential | All Other Residential | Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 7,829 10,132   10,132  
Prior year 6,807 11,281   11,281  
Two years before current year 3,843 4,394   4,394  
Three years before current year 4,991 2,733   2,733  
Four years before current year 3,573 3,360   3,360  
Prior 1,757 3,145   3,145  
Total loans 28,800 35,045   35,045  
Residential | All Other Residential | Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Four years before current year 49        
Prior 8        
Total loans 57        
Consumer | Motor Vehicle          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 279,508 240,691   240,691  
Prior year 168,763 214,364   214,364  
Two years before current year 114,456 119,968   119,968  
Three years before current year 77,048 73,327   73,327  
Four years before current year 14,313 42,281   42,281  
Prior 5,569 6,134   6,134  
Revolving Loans 9 40   40  
Total loans 659,666 696,805   696,805  
Current period gross charge offs, 2025 759     334  
Current period gross charge offs, 2024 2,380     2,090  
Current period gross charge offs, 2023 2,279     1,299  
Current period gross charge offs, 2022 4,075     1,470  
Current period gross charge offs, 2021 713     1,365  
Current period gross charge offs, Prior 249     208  
Current period gross charge offs, Total 10,455     6,766  
Consumer | Motor Vehicle | Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 279,286 240,595   240,595  
Prior year 168,244 213,846   213,846  
Two years before current year 113,956 119,373   119,373  
Three years before current year 76,182 73,021   73,021  
Four years before current year 14,119 41,747   41,747  
Prior 5,441 5,987   5,987  
Revolving Loans 9 40   40  
Total loans 657,237 694,609   694,609  
Consumer | Motor Vehicle | Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 222 96   96  
Prior year 519 518   518  
Two years before current year 500 595   595  
Three years before current year 866 306   306  
Four years before current year 194 534   534  
Prior 128 147   147  
Total loans 2,429 2,196   2,196  
Consumer | All Other Consumer          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 4,778 3,423   3,423  
Prior year 5,343 3,453   3,453  
Two years before current year 2,793 2,630   2,630  
Three years before current year 1,522 1,322   1,322  
Four years before current year 1,172 1,145   1,145  
Prior 954 1,254   1,254  
Revolving Loans 11,907 15,236   15,236  
Total loans 28,469 28,463   28,463  
Current period gross charge offs, 2025 13        
Current period gross charge offs, 2024 246     81  
Current period gross charge offs, 2023 180     85  
Current period gross charge offs, 2022 53     27  
Current period gross charge offs, 2021 44     14  
Current period gross charge offs, Prior 24     78  
Current period gross charge offs, Revolving Loans 201     250  
Current period gross charge offs, Total 761     535  
Consumer | All Other Consumer | Performing          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 4,776 3,423   3,423  
Prior year 5,276 3,399   3,399  
Two years before current year 2,726 2,593   2,593  
Three years before current year 1,503 1,282   1,282  
Four years before current year 1,137 1,143   1,143  
Prior 942 1,245   1,245  
Revolving Loans 11,842 15,215   15,215  
Total loans 28,202 28,300   28,300  
Consumer | All Other Consumer | Nonperforming Loans          
Financing Receivable, Credit Quality Indicator [Line Items]          
Current year 2        
Prior year 67 54   54  
Two years before current year 67 37   37  
Three years before current year 19 40   40  
Four years before current year 35 2   2  
Prior 12 9   9  
Revolving Loans 65 21   21  
Total loans $ 267 $ 163   $ 163