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Loans, Allowance for Credit Losses and Credit Quality - Financing Receivable Past Due (Details) $ in Thousands | Jun. 30, 2025 USD ($) loan | Dec. 31, 2024 USD ($) loan
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Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 462 |  | 648 |
Total loans |  | $ 14,533,828 | [1] | $ 14,508,378 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 36 |  | 28 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 49 |  | 37 |
Number Of Financing Receivables Total Past Due | loan |  | 547 |  | 713 |
Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 9,368 |  | $ 47,521 |
Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 4,022 |  | 2,201 |
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 15,146 |  | 37,686 |
Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 28,536 |  | 87,408 |
Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 14,505,292 |  | $ 14,420,970 |
Commercial And Industrial [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 3 |  | 7 |
Total loans | [1] | $ 3,215,480 |  | $ 3,047,671 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 3 |  | 1 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 8 |  | 5 |
Number Of Financing Receivables Total Past Due | loan |  | 14 |  | 13 |
Commercial And Industrial [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 183 |  | $ 5,807 |
Commercial And Industrial [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 1,184 |  | 5 |
Commercial And Industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 4,673 |  | 13,843 |
Commercial And Industrial [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 6,040 |  | 19,655 |
Commercial And Industrial [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 3,209,440 |  | $ 3,028,016 |
Commercial Real Estate [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 6 |  | 3 |
Total loans | [1] | $ 6,525,438 |  | $ 6,756,708 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 2 |  | 0 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 3 |  | 3 |
Number Of Financing Receivables Total Past Due | loan |  | 11 |  | 6 |
Commercial Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 4,399 |  | $ 33,087 |
Commercial Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 826 |  | 0 |
Commercial Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 6,206 |  | 20,458 |
Commercial Real Estate [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 11,431 |  | 53,545 |
Commercial Real Estate [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 6,514,007 |  | $ 6,703,163 |
Construction Loans [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 0 |  | 0 |
Total loans | [1] | $ 798,808 |  | $ 782,078 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 0 |  | 0 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 0 |  | 0 |
Number Of Financing Receivables Total Past Due | loan |  | 0 |  | 0 |
Construction Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 0 |  | $ 0 |
Construction Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 0 |  | 0 |
Construction Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 0 |  | 0 |
Construction Loans [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 0 |  | 0 |
Construction Loans [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 798,808 |  | $ 782,078 |
Small Business [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 8 |  | 6 |
Total loans | [1] | $ 300,543 |  | $ 281,781 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 14 |  | 4 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 4 |  | 3 |
Number Of Financing Receivables Total Past Due | loan |  | 26 |  | 13 |
Small Business [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 74 |  | $ 830 |
Small Business [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 272 |  | 24 |
Small Business [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 58 |  | 29 |
Small Business [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 404 |  | 883 |
Small Business [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 300,139 |  | $ 280,898 |
Residential Real Estate [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 18 |  | 27 |
Total loans | [1] | $ 2,489,166 |  | $ 2,460,600 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 6 |  | 9 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 12 |  | 10 |
Number Of Financing Receivables Total Past Due | loan |  | 36 |  | 46 |
Residential Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 3,607 |  | $ 6,310 |
Residential Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 1,398 |  | 1,401 |
Residential Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 2,134 |  | 2,224 |
Residential Real Estate [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 7,139 |  | 9,935 |
Residential Real Estate [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 2,482,027 |  | $ 2,450,665 |
Home Equity Loan [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan |  | 7 |  | 9 |
Total loans | [1] | $ 1,168,097 |  | $ 1,140,168 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan |  | 5 |  | 11 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan |  | 19 |  | 10 |
Number Of Financing Receivables Total Past Due | loan |  | 31 |  | 30 |
Home Equity Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 874 |  | $ 1,046 |
Home Equity Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 326 |  | 764 |
Home Equity Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 2,074 |  | 1,126 |
Home Equity Loan [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | 3,274 |  | 2,936 |
Home Equity Loan [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans |  | $ 1,164,823 |  | $ 1,137,232 |
Consumer - Other [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan | [3] | 420 |  | 596 |
Total loans | [3] | $ 36,296 |  | $ 39,372 | [2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan | [3] | 6 |  | 3 |
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan | [3] | 3 |  | 6 |
Number Of Financing Receivables Total Past Due | loan | [3] | 429 |  | 605 |
Consumer - Other [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans | [3] | $ 231 |  | $ 441 |
Consumer - Other [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans | [3] | 16 |  | 7 |
Consumer - Other [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans | [3] | 1 |  | 6 |
Consumer - Other [Member] | Financial Asset, Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans | [3] | 248 |  | 454 |
Consumer - Other [Member] | Financial Asset, Not Past Due |  |  |  |  |
Financing Receivable, Past Due [Line Items] |  |  |  |  |
Total loans | [3] | $ 36,048 |  | $ 38,918 |
[1] | Loan origination dates in the tables above reflect the original origination date, or the date of a material modification of a previously originated loan.
[2] | The amount of net deferred fees/costs on originated loans included in the ending balance was $6.8 million and $6.1 million at June 30, 2025 and December 31, 2024, respectively. Net unamortized discounts on acquired loans included in the ending balance were $7.5 million and $8.1 million at June 30, 2025 and December 31, 2024, respectively.
[3] | Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances. (2)The amount of net deferred fees/costs on originated loans included in the ending balance was $6.8 million and $6.1 million at June 30, 2025 and December 31, 2024, respectively. Net unamortized discounts on acquired loans included in the ending balance were $7.5 million and $8.1 million at June 30, 2025 and December 31, 2024, respectively.

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Data Type: | na
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