Loans Impaired Loans by Class (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	$ 18,212	$ 21,030	$ 18,023
Recorded Investment, With Related Allowance	11,062	10,721	13,369
Balance of impaired loans	29,274	31,751	31,392
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	20,330	22,831	19,775
Unpaid Principal Balance, With Related Allowance	11,848	11,397	13,698
Unpaid Principal Balance	32,178	34,228	33,473
Related Allowance	2,213	2,308	1,812
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	20,542	18,776	19,227
Average Recorded Investment, With Related Allowance	11,015	13,029	9,881
Average Recorded Investment	31,557	31,805	29,108
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	593	764	553
Recognized Interest Income, With Related Allowance	142	100	231
Recognized Interest Income	735	864	784
Commercial | Real Estate
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	5,235	8,718	3,791
Recorded Investment, With Related Allowance	1,074	1,042	3,999
Balance of impaired loans	6,309	9,760	7,790
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	5,492	9,161	3,996
Unpaid Principal Balance, With Related Allowance	1,093	1,059	4,116
Unpaid Principal Balance	6,585	10,220	8,112
Related Allowance	251	260	224
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	7,611	5,536	5,124
Average Recorded Investment, With Related Allowance	1,528	3,477	4,460
Average Recorded Investment	9,139	9,013	9,584
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	228	380	164
Recognized Interest Income, With Related Allowance	60	42	152
Recognized Interest Income	288	422	316
Commercial | Construction
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	958	721	741
Recorded Investment, With Related Allowance	0	0	0
Balance of impaired loans	958	721	741
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	970	721	741
Unpaid Principal Balance, With Related Allowance	0	0	0
Unpaid Principal Balance	970	721	741
Related Allowance	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	936	762	62
Average Recorded Investment, With Related Allowance	0	0	699
Average Recorded Investment	936	762	761
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	47	43	38
Recognized Interest Income, With Related Allowance	0	0	0
Recognized Interest Income	47	43	38
Commercial | Other
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	756	1,468	2,591
Recorded Investment, With Related Allowance	6,319	7,791	7,327
Balance of impaired loans	7,075	9,259	9,918
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	786	1,555	2,671
Unpaid Principal Balance, With Related Allowance	6,925	8,216	7,371
Unpaid Principal Balance	7,711	9,771	10,042
Related Allowance	1,273	1,696	1,309
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	965	2,037	1,908
Average Recorded Investment, With Related Allowance	6,778	7,471	2,584
Average Recorded Investment	7,743	9,508	4,492
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	29	32	36
Recognized Interest Income, With Related Allowance	0	5	0
Recognized Interest Income	29	37	36
Municipal
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	0	0	0
Recorded Investment, With Related Allowance	0	0	0
Balance of impaired loans	0	0	0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	0	0	0
Unpaid Principal Balance, With Related Allowance	0	0	0
Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	0	0	0
Average Recorded Investment, With Related Allowance	0	0	0
Average Recorded Investment	0	0	0
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	0	0	0
Recognized Interest Income, With Related Allowance	0	0	0
Recognized Interest Income	0	0	0
Residential | Construction
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	0	0	0
Recorded Investment, With Related Allowance	0	0	0
Balance of impaired loans	0	0	0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	0	0	0
Unpaid Principal Balance, With Related Allowance	0	0	0
Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	0	0	0
Average Recorded Investment, With Related Allowance	0	0	0
Average Recorded Investment	0	0	0
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	0	0	0
Recognized Interest Income, With Related Allowance	0	0	0
Recognized Interest Income	0	0	0
Residential | Term
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	10,176	9,136	9,769
Recorded Investment, With Related Allowance	2,263	1,768	1,979
Balance of impaired loans	12,439	10,904	11,748
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	11,931	10,317	10,909
Unpaid Principal Balance, With Related Allowance	2,412	1,998	2,144
Unpaid Principal Balance	14,343	12,315	13,053
Related Allowance	237	335	255
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	10,033	9,427	10,770
Average Recorded Investment, With Related Allowance	2,424	1,982	2,106
Average Recorded Investment	12,457	11,409	12,876
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	269	289	297
Recognized Interest Income, With Related Allowance	82	53	79
Recognized Interest Income	351	342	376
Home Equity LIne of Credit
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	1,087	972	1,115
Recorded Investment, With Related Allowance	1,401	120	64
Balance of impaired loans	2,488	1,092	1,179
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	1,151	1,035	1,429
Unpaid Principal Balance, With Related Allowance	1,412	124	67
Unpaid Principal Balance	2,563	1,159	1,496
Related Allowance	447	17	24
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	997	1,001	1,351
Average Recorded Investment, With Related Allowance	283	99	32
Average Recorded Investment	1,280	1,100	1,383
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	20	20	18
Recognized Interest Income, With Related Allowance	0	0	0
Recognized Interest Income	20	20	18
Consumer
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, No Related Allowance	0	15	16
Recorded Investment, With Related Allowance	5	0	0
Balance of impaired loans	5	15	16
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, No Related Allowance	0	42	29
Unpaid Principal Balance, With Related Allowance	6	0	0
Unpaid Principal Balance	6	42	29
Related Allowance	5	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, No Related Allowance	0	13	12
Average Recorded Investment, With Related Allowance	2	0	0
Average Recorded Investment	2	13	12
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized Interest Income, No Related Allowance	0	0	0
Recognized Interest Income, With Related Allowance	0	0	0
Recognized Interest Income	$ 0	$ 0	$ 0