Allowance For Loan Losses - Troubled Debt Restructures (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) restructuring	Jun. 30, 2019 USD ($) restructuring	Jun. 30, 2020 USD ($) restructuring	Jun. 30, 2019 USD ($) restructuring	Dec. 31, 2019 USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Troubled Debt Restructure (TDR) loans	$ 19,300,000		$ 19,300,000		$ 21,100,000
TDR loans on accrual status	12,200,000		12,200,000		17,100,000
TDR loans included in non-performing loans	$ 7,100,000		$ 7,100,000		$ 4,000,000.0
Number of restructurings | restructuring	2	5	8	12
Pre-modification outstanding recorded investment	$ 1,314,000	$ 1,844,000	$ 5,229,000	$ 2,774,000
Post-modification recorded investment	$ 1,518,000	$ 1,848,000	5,227,000	2,243,000
Charge-offs associated with new TDRs			$ 0	$ 0
Number of TDRs that defaulted | restructuring	2	0	4	2
Post-modification outstanding recorded investment, TDRs that defaulted	$ 64,000		$ 1,807,000	$ 172,000
Specific reserves allocated to TDRs	$ 1,320,000	$ 89,000	$ 1,320,000	$ 89,000
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	0	2	0	3
Pre-modification outstanding recorded investment	$ 0	$ 1,626,000	$ 0	$ 2,047,000
Post-modification recorded investment	$ 0	$ 1,626,000	$ 0	$ 1,626,000
Number of TDRs that defaulted | restructuring	0		0	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0		$ 0	$ 0
Commercial construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	2	0	6	0
Pre-modification outstanding recorded investment	$ 1,314,000	$ 0	$ 4,754,000	$ 0
Post-modification recorded investment	$ 1,518,000	$ 0	$ 4,825,000	$ 0
Number of TDRs that defaulted | restructuring	0		2	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0		$ 1,743,000	$ 0
Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	0	2	1	7
Pre-modification outstanding recorded investment	$ 0	$ 212,000	$ 474,000	$ 406,000
Post-modification recorded investment	$ 0	$ 216,000	$ 402,000	$ 299,000
Number of TDRs that defaulted | restructuring	2		2	2
Post-modification outstanding recorded investment, TDRs that defaulted	$ 64,000		$ 64,000	$ 172,000
SBA Paycheck Protection Program
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	0	0	0	0
Pre-modification outstanding recorded investment	$ 0	$ 0	$ 0	$ 0
Post-modification recorded investment	$ 0	$ 0	$ 0	$ 0
Number of TDRs that defaulted | restructuring	0		0	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0		$ 0	$ 0
Residential mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	0	0	0	1
Pre-modification outstanding recorded investment	$ 0	$ 0	$ 0	$ 315,000
Post-modification recorded investment	$ 0	$ 0	$ 0	$ 312,000
Number of TDRs that defaulted | restructuring	0		0	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0		$ 0	$ 0
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	0	0	0	0
Pre-modification outstanding recorded investment	$ 0	$ 0	$ 0	$ 0
Post-modification recorded investment	$ 0	$ 0	$ 0	$ 0
Number of TDRs that defaulted | restructuring	0		0	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0		$ 0	$ 0
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring	0	1	1	1
Pre-modification outstanding recorded investment	$ 0	$ 6,000	$ 1,000	$ 6,000
Post-modification recorded investment	$ 0	$ 6,000	$ 0	$ 6,000
Number of TDRs that defaulted | restructuring	0		0	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0		$ 0	$ 0
Extended maturity date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring			2	0
Post-modification recorded investment			$ 1,743,000	$ 0
Temporary payment reduction and payment re-amortization of remaining principal over extended term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring			2	7
Post-modification recorded investment			$ 975,000	$ 89,000
Temporary interest only payment plan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring			0	2
Post-modification recorded investment			$ 0	$ 395,000
Forbearance of post default rights
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring			4	0
Post-modification recorded investment			$ 2,509,000	$ 0
Other payment concessions
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of restructurings | restructuring			0	3
Post-modification recorded investment			$ 0	$ 1,759,000