Loans - Modification Statuses by Portfolio Segment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan	Dec. 31, 2018 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	74	81
Balance	$ 1,476,761	$ 1,297,075	$ 1,238,283
Out of Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance	$ 213,819
Commercial/Municipal Portfolio Segment \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	601
Percentage of loans receivable, by type	1.000
Balance	$ 238,408
Percentage of balance	100.00%
Commercial/Municipal Portfolio Segment \| Paid Off \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	61
Percentage of loans receivable, by type	0.100
Balance	$ 9,027
Percentage of balance	4.00%
Commercial/Municipal Portfolio Segment \| Subsequent Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	54
Percentage of loans receivable, by type	0.090
Balance	$ 32,724
Percentage of balance	14.00%
Commercial/Municipal Portfolio Segment \| Still in Original Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	16
Percentage of loans receivable, by type	0.030
Balance	$ 7,244
Percentage of balance	3.00%
Commercial/Municipal Portfolio Segment \| Out of Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	470
Percentage of loans receivable, by type	0.780
Balance	$ 189,413
Percentage of balance	79.00%
Residential \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	362
Percentage of loans receivable, by type	1.000
Balance	$ 51,566
Percentage of balance	100.00%
Residential \| Paid Off \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	27
Percentage of loans receivable, by type	0.070
Balance	$ 5,930
Percentage of balance	12.00%
Residential \| Subsequent Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	154
Percentage of loans receivable, by type	0.430
Balance	$ 19,468
Percentage of balance	38.00%
Residential \| Still in Original Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	27
Percentage of loans receivable, by type	0.070
Balance	$ 2,615
Percentage of balance	5.00%
Residential \| Out of Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	154
Percentage of loans receivable, by type	0.430
Balance	$ 23,553
Percentage of balance	45.00%
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	1	0
Balance	$ 25,857	$ 26,503	$ 24,860
Consumer \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	68
Percentage of loans receivable, by type	1.000
Balance	$ 1,129
Percentage of balance	100.00%
Consumer \| Paid Off \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	11
Percentage of loans receivable, by type	0.160
Balance	$ 118
Percentage of balance	10.00%
Consumer \| Subsequent Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	3
Percentage of loans receivable, by type	0.040
Balance	$ 104
Percentage of balance	9.00%
Consumer \| Still in Original Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	4
Percentage of loans receivable, by type	0.060
Balance	$ 53
Percentage of balance	5.00%
Consumer \| Out of Modification \| Exemption from Troubled Debt Restructure Designation, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Units \| loan	50
Percentage of loans receivable, by type	0.740
Balance	$ 854
Percentage of balance	76.00%