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
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.