Loans, net and allowance for loan losses - Major Classification of Loans by Past Due Status (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 14,349	$ 15,392
Current	1,844,450	1,807,874
Total Loans	1,858,799	1,823,266
Loans > 90 Days and Accruing	341	923
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4,010	6,104
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	745	2,134
Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	9,594	7,154
Commercial
Financing Receivable, Recorded Investment, Past Due
Total Past Due	5,023	1,828
Current	508,632	492,306
Total Loans	513,655	494,134
Loans > 90 Days and Accruing	8
Commercial \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	385	973
Commercial \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	136	79
Commercial \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4,502	776
Real estate Commercial
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4,446	4,843
Current	931,132	902,960
Total Loans	935,578	907,803
Loans > 90 Days and Accruing	148	73
Real estate Commercial \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	1,200	1,889
Real estate Commercial \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	54	218
Real estate Commercial \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	3,192	2,736
Real estate Residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	298,527	299,876
Real estate Residential
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4,006	7,461
Current	294,521	292,415
Total Loans	298,527	299,876
Loans > 90 Days and Accruing	185	850
Real estate Residential \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	1,930	2,486
Real estate Residential \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	427	1,545
Real estate Residential \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	1,649	3,430
Consumer
Financing Receivable, Recorded Investment, Past Due
Total Past Due	874	1,260
Current	110,165	120,193
Total Loans	111,039	121,453
Consumer \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	495	756
Consumer \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	128	292
Consumer \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 251	$ 212

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

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