Loans Loan Categories and Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	$ 9,791	$ 13,177	$ 9,777
Current Loans	2,270,517	2,183,038	2,048,085
Total Loans	2,280,308	2,196,215	2,057,862
Loans 90 or More Days Past Due and Still Accruing Interest	457	1,225	170
Nonaccrual Loans	4,949	4,159	3,880
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	6,660	5,879	6,776
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	1,289	4,093	1,008
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	1,842	3,205	1,993
Commercial
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	192	170	46
Current Loans	138,139	136,720	118,835
Total Loans	138,331	136,890	118,881
Loans 90 or More Days Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	58	403	633
Commercial \| Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	119	121	3
Commercial \| Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	73	49	15
Commercial \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	0	0	28
Commercial Real Estate Portfolio Segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	328	897	963
Current Loans	489,946	483,665	463,430
Total Loans	490,274	484,562	464,393
Loans 90 or More Days Past Due and Still Accruing Interest	220	0	0
Nonaccrual Loans	248	789	963
Commercial Real Estate Portfolio Segment \| Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	0	108	0
Commercial Real Estate Portfolio Segment \| Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	0	0	0
Commercial Real Estate Portfolio Segment \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	328	789	963
Consumer Loans Financing
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	6,060	8,077	5,720
Current Loans	772,964	711,433	656,188
Total Loans	779,024	719,510	661,908
Loans 90 or More Days Past Due and Still Accruing Interest	45	144	28
Nonaccrual Loans	412	658	459
Consumer Loans Financing \| Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	4,935	5,369	4,769
Consumer Loans Financing \| Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	948	2,136	720
Consumer Loans Financing \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	177	572	231
Residential
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	3,211	4,033	3,048
Current Loans	869,468	851,220	809,632
Total Loans	872,679	855,253	812,680
Loans 90 or More Days Past Due and Still Accruing Interest	192	1,081	142
Nonaccrual Loans	4,231	2,309	1,825
Residential \| Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	1,606	281	2,004
Residential \| Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	268	1,908	273
Residential \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	$ 1,337	$ 1,844	$ 771

Amount of financing receivable 90 days or more past due and still accruing.

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