Loans, Allowance for Credit Losses and Credit Quality Textual (Details) - USD ($)		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021		Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Days To Be Termed As Non Accrual Loans		90 days
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease) by percentage		(1.60%)
(Release of) provision for credit losses		$ (2,000,000)	$ (2,500,000)
Interest Receivable		39,400,000	33,400,000
Off-Balance Sheet, Credit Loss, Liability		1,500,000			$ 1,500,000
Loans with active Deferrals		304,500,000			383,100,000
Allowance for Loan and Lease Losses, Write-offs		(706,000)
Financing Receivable, Troubled Debt Restructuring, Increase (Decrease) from Modification			18,212,000
us-gaap_FinancingReceivableTroubledDebtRestructuringIncreaseDecreaseFromModification		14,300,000
Financing Receivable, after Allowance for Credit Loss		665,591,000	803,487,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		0	0
Loans with active Deferrals		304,500,000			383,100,000
Interest Receivable		39,400,000	33,400,000
Loans and Leases Receivable, Allowance		(144,518,000)	(107,549,000)	[1]	(146,922,000)
Off-Balance Sheet, Credit Loss, Liability		1,500,000			1,500,000
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)		2,400,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		0	0
US Government Insured Loan Program [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss			846,300,000
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
(Release of) provision for credit losses			2,388,000
Financing Receivable, before Allowance for Credit Loss		1,566,192,000			$ 1,563,279,000
Allowance for Loan and Lease Losses, Write-offs		0
Financing Receivable, after Allowance for Credit Loss		139,674,000	442,018,000
Loans and Leases Receivable, Allowance	[1]		(20,207,000)
Commercial And Industrial [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		403,000	$ 17,912,000
Loans Insured or Guaranteed by US Government Authorities
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 99,600,000

[1] Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $39.4 million and $33.4 million as of March 31, 2022 and March 31, 2021, respectively.