Loans, net and allowance for loan losses - Major Classification of Loans by Past Due Status (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 17,200	$ 12,801
Current	2,005,955	1,925,439
Total Loans	2,023,155	1,938,240
Loans > 90 Days and Accruing	423	378
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	7,501	3,688
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	601	1,525
Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	9,098	7,588
Commercial
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4,580	3,111
Current	533,369	519,846
Total Loans	537,949	522,957
Commercial \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	196	75
Commercial \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	11
Commercial \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4,373	3,036
Real estate Commercial
Financing Receivable, Recorded Investment, Past Due
Total Past Due	6,306	3,866
Current	1,075,818	1,007,557
Total Loans	1,082,124	1,011,423
Real estate Commercial \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	2,861	926
Real estate Commercial \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	187	175
Real estate Commercial \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	3,258	2,765
Real estate Residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	307,215	301,378
Real estate Residential
Financing Receivable, Recorded Investment, Past Due
Total Past Due	5,446	4,917
Current	301,769	296,461
Total Loans	307,215	301,378
Loans > 90 Days and Accruing	423	378
Real estate Residential \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	3,924	2,164
Real estate Residential \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	256	1,227
Real estate Residential \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	1,266	1,526
Consumer
Financing Receivable, Recorded Investment, Past Due
Total Past Due	868	907
Current	94,999	101,575
Total Loans	95,867	102,482
Consumer \| 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	520	523
Consumer \| 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	147	123
Consumer \| Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 201	$ 261

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

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