Loans, Allowance for Credit Losses and Credit Quality Troubled Debt Restructurings (Details)	3 Months Ended				9 Months Ended
	Sep. 30, 2022 USD ($) contract		Sep. 30, 2021 USD ($) contract		Sep. 30, 2022 USD ($) contract	Sep. 30, 2021 USD ($) contract		Dec. 31, 2021 USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	1		0		1	8
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 68,000	[1]	$ 0	[1]	$ 68,000	$ 18,301,000	[1]
Financing Receivable, Troubled Debt Restructuring, Postmodification	67,000	[1]	$ 0	[1]	67,000	$ 18,301,000	[1]
Tdrs Recorded Investment On Accrual Status	11,549,000				11,549,000			$ 14,635,000
Tdrs Recorded Investment On Nonaccrual Status	1,538,000				1,538,000			1,993,000
Financing Receivable Recorded Investment Trouble Debt Restructuring	13,087,000				13,087,000			16,628,000
Additional Commitments To Lend To Borrower For Trouble Debt Restructuring	$ 137,000				$ 137,000			$ 190,000
Commercial And Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	1		0		1	1
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 68,000		$ 0		$ 68,000	$ 14,148,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 67,000		$ 0		$ 67,000	$ 14,148,000
Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract			0			5
Financing Receivable, Troubled Debt Restructuring, Premodification			$ 0			$ 3,964,000
Financing Receivable, Troubled Debt Restructuring, Postmodification			$ 0			$ 3,964,000
Small Business [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract			0			2
Financing Receivable, Troubled Debt Restructuring, Premodification			$ 0			$ 189,000
Financing Receivable, Troubled Debt Restructuring, Postmodification			$ 0			$ 189,000

[1] The pre-modification and post-modification balances represent the legal principal balance of the loan. Activity presented in the table above includes $14.3 million of modifications on existing TDRs occurring during the nine months ended September 30, 2021.