Loans, Allowance for Credit Losses and Credit Quality - Financing Receivable Past Due (Details) $ in Thousands		Mar. 31, 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		475		648
Total loans		$ 14,491,969	[1]	$ 14,508,378	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan		34		28
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan		44		37
Number Of Financing Receivables Total Past Due | loan		553		713
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		$ 13,811		$ 47,521
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		3,040		2,201
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		51,306		37,686
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans		68,157		87,408
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans		$ 14,423,812		$ 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		9		7
Total loans	[1]	$ 3,110,432		$ 3,047,671	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan		1		1
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan		7		5
Number Of Financing Receivables Total Past Due | loan		17		13
Commercial And Industrial [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		$ 8,087		$ 5,807
Commercial And Industrial [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		25		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		9,545		13,843
Commercial And Industrial [Member] | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans		17,657		19,655
Commercial And Industrial [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans		$ 3,092,775		$ 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		4		3
Total loans	[1]	$ 6,651,475		$ 6,756,708	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan		1		0
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan		5		3
Number Of Financing Receivables Total Past Due | loan		10		6
Commercial Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		$ 629		$ 33,087
Commercial Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		155		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		37,917		20,458
Commercial Real Estate [Member] | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans		38,701		53,545
Commercial Real Estate [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans		$ 6,612,774		$ 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]	$ 796,162		$ 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		$ 796,162		$ 782,078
Small Business [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan		18		6
Total loans	[1]	$ 289,148		$ 281,781	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan		5		4
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan		5		3
Number Of Financing Receivables Total Past Due | loan		28		13
Small Business [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		$ 460		$ 830
Small Business [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		64		24
Small Business [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		83		29
Small Business [Member] | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans		607		883
Small Business [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans		$ 288,541		$ 280,898
Residential Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan		12		27
Total loans	[1]	$ 2,465,731		$ 2,460,600	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan		7		9
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan		11		10
Number Of Financing Receivables Total Past Due | loan		30		46
Residential Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		$ 3,043		$ 6,310
Residential Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		1,844		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		2,449		2,224
Residential Real Estate [Member] | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans		7,336		9,935
Residential Real Estate [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans		$ 2,458,395		$ 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		15		9
Total loans	[1]	$ 1,143,966		$ 1,140,168	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan		11		11
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan		9		10
Number Of Financing Receivables Total Past Due | loan		35		30
Home Equity Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		$ 1,292		$ 1,046
Home Equity Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans		935		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		1,306		1,126
Home Equity Loan [Member] | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans		3,533		2,936
Home Equity Loan [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans		$ 1,140,433		$ 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]	417		596
Total loans	[3]	$ 35,055		$ 39,372	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	[3]	9		3
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	[3]	7		6
Number Of Financing Receivables Total Past Due | loan	[3]	433		605
Consumer - Other [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans	[3]	$ 300		$ 441
Consumer - Other [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total loans	[3]	17		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]	6		6
Consumer - Other [Member] | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total loans	[3]	323		454
Consumer - Other [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total loans	[3]	$ 34,732		$ 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 $6.0 million and $6.1 million at March 31, 2025 and December 31, 2024, respectively. Net unamortized discounts on acquired loans included in the ending balance were $7.7 million and $8.1 million at March 31, 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 $6.0 million and $6.1 million at March 31, 2025 and December 31, 2024, respectively. Net unamortized discounts on acquired loans included in the ending balance were $7.7 million and $8.1 million at March 31, 2025 and December 31, 2024, respectively.