Loans Past-due Status of Loans by Class (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 15,017	$ 13,375
Current	1,282,058	1,224,908
Ending balance	1,297,075	1,238,283	$ 1,164,139
90 Plus Days And Accruing	1,560	351
Commercial | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,774	2,051
Current	371,036	351,192
Ending balance	372,810	353,243	323,809
90 Plus Days And Accruing	0	0
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	271	10
Current	37,813	27,294
Ending balance	38,084	27,304	38,056
90 Plus Days And Accruing	0	0
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	5,028	580
Current	213,745	195,811
Ending balance	218,773	196,391	181,528
90 Plus Days And Accruing	1,464	0
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Current	41,288	51,128
Ending balance	41,288	51,128	33,391
90 Plus Days And Accruing	0	0
Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	76
Current	14,813	17,667
Ending balance	14,813	17,743	17,868
90 Plus Days And Accruing	0	0
Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	4,640	6,638
Current	487,815	462,507
Ending balance	492,455	469,145	432,661
90 Plus Days And Accruing	86	339
Home Equity LIne of Credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,957	3,731
Current	89,392	94,738
Ending balance	92,349	98,469	111,302
90 Plus Days And Accruing	0	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	347	289
Current	26,156	24,571
Ending balance	26,503	24,860	$ 25,524
90 Plus Days And Accruing	10	12
30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	6,139	5,958
30-59 Days Past Due | Commercial | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	786	1,274
30-59 Days Past Due | Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
30-59 Days Past Due | Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,764	455
30-59 Days Past Due | Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
30-59 Days Past Due | Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	76
30-59 Days Past Due | Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,129	1,097
30-59 Days Past Due | Home Equity LIne of Credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,169	2,819
30-59 Days Past Due | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	291	237
60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,092	3,977
60-89 Days Past Due | Commercial | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	377	0
60-89 Days Past Due | Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	14	10
60-89 Days Past Due | Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	465	5
60-89 Days Past Due | Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
60-89 Days Past Due | Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
60-89 Days Past Due | Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,132	3,518
60-89 Days Past Due | Home Equity LIne of Credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	58	419
60-89 Days Past Due | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	46	25
90 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	6,786	3,440
90 Days Past Due | Commercial | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	611	777
90 Days Past Due | Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	257	0
90 Days Past Due | Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,799	120
90 Days Past Due | Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
90 Days Past Due | Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
90 Days Past Due | Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,379	2,023
90 Days Past Due | Home Equity LIne of Credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,730	493
90 Days Past Due | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 10	$ 27