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Allowance for Credit Losses and Credit Quality of Loans, Summary (Details) - USD ($) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses | $ 116,000 | $ 114,400 | $ 100,800 | $ 92,000
Percentage of allowance of credit losses | 1.16% | 1.19% |  |
Forecast scenario weighting, baseline | 80.00% | 70.00% |  |
Forecast scenario weighting, downside | 20.00% | 30.00% |  |
Salisbury Bank [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Loans purchased with credit deterioration | $ 0 | $ 219,500 |  |
Allowance for credit losses on loans purchased |  | 5,800 |  |
Allowance for credit losses at acquisition |  | 14,500 |  |
Salisbury Bank [Member] | PCD [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses at acquisition |  | 5,800 |  |
Salisbury Bank [Member] | Non-PCD [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses at acquisition |  | 8,800 |  |
ASU 2022-02 [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses |  | 114,400 | 100,152 |
Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASU 2022-02 [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses |  |  | (600) |
Accrued Interest Receivable [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses | 0 | 0 |  |
AIR on loans | $ 34,800 | $ 34,100 |  |
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] | Other Assets | Other Assets |  |
Residential [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses | $ 26,560 | $ 22,070 | 15,127 | 18,806
Amount of loans purchased | $ 3,000 | $ 3,800 |  |
Premium on loans purchased | 7.00% | 7.00% |  |
Allowance for credit losses on loans purchased | $ 31 | $ 31 |  |
Residential [Member] | ASU 2022-02 [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses |  | 22,070 | 14,539 |
Consumer Loans [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses | $ 43,987 | 46,427 | 50,951 | $ 44,253
Consumer Loans [Member] | ASU 2022-02 [Member] |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |
Allowance for credit losses |  | $ 46,427 | $ 50,951 |

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- Definition Percentage of allowance for credit loss to total financing receivable outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (1) -Publisher SEC + Details
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