Loans and Allowance for Loan Losses - Past due aging analysis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	$ 1,686,087	$ 1,701,850
Performing
Past due aging analysis of loans
Accruing Current	1,676,636	1,688,311
Nonperforming
Past due aging analysis of loans
Nonperforming	5,107	6,963
30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	4,299	6,576
90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due	45
Commercial
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	951,457	969,634
Commercial \| Performing
Past due aging analysis of loans
Accruing Current	945,833	961,724
Commercial \| Nonperforming
Past due aging analysis of loans
Nonperforming	3,568	5,095
Commercial \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	2,011	2,815
Commercial \| 90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due	45
Commercial \| Commercial and industrial
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	485,183	510,706
Commercial \| Commercial and industrial \| Performing
Past due aging analysis of loans
Accruing Current	481,480	504,313
Commercial \| Commercial and industrial \| Nonperforming
Past due aging analysis of loans
Nonperforming	2,097	3,578
Commercial \| Commercial and industrial \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	1,561	2,815
Commercial \| Commercial and industrial \| 90 Days or More Past Due \| Performing
Past due aging analysis of loans
Past due	45
Commercial \| Real estate construction
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	21,674	18,965
Commercial \| Real estate construction \| Performing
Past due aging analysis of loans
Accruing Current	21,224	18,965
Commercial \| Real estate construction \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	450
Commercial \| Commercial real estate
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	444,600	439,963
Commercial \| Commercial real estate \| Performing
Past due aging analysis of loans
Accruing Current	443,129	438,446
Commercial \| Commercial real estate \| Nonperforming
Past due aging analysis of loans
Nonperforming	1,471	1,517
Consumer
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	734,630	732,216
Consumer \| Performing
Past due aging analysis of loans
Accruing Current	730,803	726,587
Consumer \| Nonperforming
Past due aging analysis of loans
Nonperforming	1,539	1,868
Consumer \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	2,288	3,761
Consumer \| Residential \| Real estate first mortgage
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	459,763	448,143
Consumer \| Residential \| Real estate first mortgage \| Performing
Past due aging analysis of loans
Accruing Current	456,981	444,470
Consumer \| Residential \| Real estate first mortgage \| Nonperforming
Past due aging analysis of loans
Nonperforming	677	1,262
Consumer \| Residential \| Real estate first mortgage \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	2,105	2,411
Consumer \| Residential \| Real estate junior lien
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	182,516	188,855
Consumer \| Residential \| Real estate junior lien \| Performing
Past due aging analysis of loans
Accruing Current	181,646	187,502
Consumer \| Residential \| Real estate junior lien \| Nonperforming
Past due aging analysis of loans
Nonperforming	856	584
Consumer \| Residential \| Real estate junior lien \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	14	769
Consumer \| Other revolving and installment
Past due aging analysis of loans
Loans and Leases Receivable, Gross, Total	92,351	95,218
Consumer \| Other revolving and installment \| Performing
Past due aging analysis of loans
Accruing Current	92,176	94,615
Consumer \| Other revolving and installment \| Nonperforming
Past due aging analysis of loans
Nonperforming	6	22
Consumer \| Other revolving and installment \| 30 - 89 Days Past Due \| Performing
Past due aging analysis of loans
Past due	$ 169	$ 581

Amount of financing receivable not past due.

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Amount of financing receivable on nonaccrual status.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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