Loans and Allowance for Loan Losses - Past due aging analysis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	$ 1,758,277	$ 1,721,279
Performing
Past due aging analysis of loans
Accruing Current	1,746,139	1,711,189
Nonaccrual	6,959	7,379
Loans and Leases Receivable, Gross, Total	1,758,277	1,721,279
30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	5,168	2,263
90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due	11	448
Commercial
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	1,050,230	1,000,225
Commercial \| Performing
Past due aging analysis of loans
Accruing Current	1,041,186	992,858
Nonaccrual	6,004	6,302
Loans and Leases Receivable, Gross, Total	1,050,230	1,000,225
Commercial \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	3,040	1,065
Commercial \| Commercial and industrial
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	502,637	479,144
Commercial \| Commercial and industrial \| Performing
Past due aging analysis of loans
Accruing Current	497,635	473,900
Nonaccrual	4,564	4,862
Loans and Leases Receivable, Gross, Total	502,637	479,144
Commercial \| Commercial and industrial \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	438	382
Commercial \| Real estate construction
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	25,487	26,378
Commercial \| Real estate construction \| Performing
Past due aging analysis of loans
Accruing Current	25,487	26,251
Loans and Leases Receivable, Gross, Total	25,487	26,378
Commercial \| Real estate construction \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due		127
Commercial \| Commercial real estate
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	522,106	494,703
Commercial \| Commercial real estate \| Performing
Past due aging analysis of loans
Accruing Current	518,064	492,707
Nonaccrual	1,440	1,440
Loans and Leases Receivable, Gross, Total	522,106	494,703
Commercial \| Commercial real estate \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	2,602	556
Consumer
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	708,047	721,054
Consumer \| Performing
Past due aging analysis of loans
Accruing Current	704,953	718,331
Nonaccrual	955	1,077
Loans and Leases Receivable, Gross, Total	708,047	721,054
Consumer \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	2,128	1,198
Consumer \| 90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due	11	448
Consumer \| Residential \| Real estate first mortgage
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	457,895	457,155
Consumer \| Residential \| Real estate first mortgage \| Performing
Past due aging analysis of loans
Accruing Current	455,580	455,244
Nonaccrual	741	797
Loans and Leases Receivable, Gross, Total	457,895	457,155
Consumer \| Residential \| Real estate first mortgage \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	1,574	666
Consumer \| Residential \| Real estate first mortgage \| 90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due		448
Consumer \| Residential \| Real estate junior lien
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	170,538	177,373
Consumer \| Residential \| Real estate junior lien \| Performing
Past due aging analysis of loans
Accruing Current	170,099	176,915
Nonaccrual	191	274
Loans and Leases Receivable, Gross, Total	170,538	177,373
Consumer \| Residential \| Real estate junior lien \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	237	184
Consumer \| Residential \| Real estate junior lien \| 90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due	11
Consumer \| Other revolving and installment
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	79,614	86,526
Consumer \| Other revolving and installment \| Performing
Past due aging analysis of loans
Accruing Current	79,274	86,172
Nonaccrual	23	6
Loans and Leases Receivable, Gross, Total	79,614	86,526
Consumer \| Other revolving and installment \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	$ 317	$ 348

Amount of financing receivable not past due.

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Amount of financing receivable on nonaccrual status.

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