Loans, Allowance for Credit Losses and Credit Quality - Finance Receivable, Nonaccrual (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance	[1]	$ 49,089	$ 43,040
Financing Receivable, Nonaccrual, No Allowance	[1]	7,852	11,343
Financing Receivable, Nonaccrual	[1]	56,941	54,383
Commercial And Industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		17,640	19,890
Financing Receivable, Nonaccrual, No Allowance			298
Financing Receivable, Nonaccrual		17,640	20,188
Commercial Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		16,361	11,911
Financing Receivable, Nonaccrual, No Allowance		7,852	11,041
Financing Receivable, Nonaccrual		24,213	22,952
Small Business [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		316	394
Financing Receivable, Nonaccrual, No Allowance		0	4
Financing Receivable, Nonaccrual		316	398
Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		9,947	7,634
Financing Receivable, Nonaccrual, No Allowance		0	0
Financing Receivable, Nonaccrual		9,947	7,634
Home Equity Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		4,805	3,171
Financing Receivable, Nonaccrual, No Allowance		0	0
Financing Receivable, Nonaccrual		4,805	3,171
Consumer - Other [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		20	40
Financing Receivable, Nonaccrual, No Allowance		0	0
Financing Receivable, Nonaccrual		$ 20	$ 40

[1] (1)Nonaccrual balances reported above without an allowance for credit losses are attributable to loans evaluated on an individual basis where it was determined that there was no risk of loss due to sufficient underlying collateral values.