Loans, Allowance for Credit Losses and Credit Quality Textual (Details) - USD ($)		3 Months Ended				6 Months Ended
		Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 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						(1.80%)
Release of provision for credit losses		$ 0		$ (5,000,000)		$ (2,000,000)		$ (7,500,000)
Interest Receivable		39,000,000		29,900,000		39,000,000		29,900,000
Off-Balance Sheet, Credit Loss, Liability		1,300,000				1,300,000				$ 1,500,000
Loans with active Deferrals		197,400,000				197,400,000				383,100,000
Allowance for Loan and Lease Losses, Write-offs		(544,000)
Financing Receivable, Troubled Debt Restructuring, Increase (Decrease) from Modification								18,301,000
us-gaap_FinancingReceivableTroubledDebtRestructuringIncreaseDecreaseFromModification		14,300,000
Financing Receivable, after Allowance for Credit Loss		1,636,427,000		1,443,866,000		1,636,427,000		1,443,866,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		0						0
Loans with active Deferrals		197,400,000				197,400,000				383,100,000
Interest Receivable		39,000,000		29,900,000		39,000,000		29,900,000
Loans and Leases Receivable, Allowance		(144,319,000)	[1]	(102,357,000)	[1]	(144,319,000)	[1]	(102,357,000)	[1]	(146,922,000)
Off-Balance Sheet, Credit Loss, Liability		1,300,000				1,300,000				1,500,000
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)						2,600,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		0						0
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Release of provision for credit losses				(3,068,000)		(337,000)		(680,000)
Financing Receivable, before Allowance for Credit Loss		1,541,046,000				1,541,046,000				$ 1,563,279,000
Allowance for Loan and Lease Losses, Write-offs		0
Financing Receivable, after Allowance for Credit Loss		221,010,000		575,392,000		221,010,000		575,392,000
Loans and Leases Receivable, Allowance	[1]	(14,107,000)		(17,032,000)		(14,107,000)		(17,032,000)
Commercial And Industrial [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		354,000		$ 18,026,000		354,000		$ 18,026,000
Loans Insured or Guaranteed by US Government Authorities
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 30,600,000				$ 30,600,000

[1] Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $39.0 million and $29.9 million as of June 30, 2022 and June 30, 2021, respectively.