Loans Receivable - Age analysis of past due loans and leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Age Analysis of Past Due Loans and Leases
Total past due	$ 2,628	$ 809
Current	931,195	835,047
Total Accruing Loans and leases	933,823	835,856
Nonaccrual loans and leases	3,930	3,931
Loans and Leases Receivable, Gross, Total	$ 937,753	$ 839,787
Delinquency percentage	0.70%	0.56%
Loans at fair value	$ 11,278	$ 11,422
Commercial mortgage
Age Analysis of Past Due Loans and Leases
Current	355,869	324,169
Total Accruing Loans and leases	355,869	324,169
Nonaccrual loans and leases	1,549	1,224
Loans and Leases Receivable, Gross, Total	$ 357,418	$ 325,393
Delinquency percentage	0.43%	0.38%
Home equity lines and loans
Age Analysis of Past Due Loans and Leases
Total past due	$ 592	$ 348
Current	82,563	81,855
Total Accruing Loans and leases	83,155	82,203
Nonaccrual loans and leases	257	83
Loans and Leases Receivable, Gross, Total	$ 83,412	$ 82,286
Delinquency percentage	1.02%	0.52%
Residential mortgage
Age Analysis of Past Due Loans and Leases
Total past due		$ 195
Current	$ 54,574	51,018
Total Accruing Loans and leases	54,574	51,213
Nonaccrual loans and leases	1,698	2,147
Loans and Leases Receivable, Gross, Total	$ 56,272	$ 53,360
Delinquency percentage	3.02%	4.39%
Construction
Age Analysis of Past Due Loans and Leases
Total past due	$ 1,519
Current	152,944	$ 116,906
Total Accruing Loans and leases	154,463	116,906
Loans and Leases Receivable, Gross, Total	$ 154,463	116,906
Delinquency percentage	0.98%
Commercial and industrial
Age Analysis of Past Due Loans and Leases
Total past due	$ 394	217
Current	283,556	259,112
Total Accruing Loans and leases	283,950	259,329
Nonaccrual loans and leases	426	477
Loans and Leases Receivable, Gross, Total	$ 284,376	$ 259,806
Delinquency percentage	0.29%	0.27%
Consumer
Age Analysis of Past Due Loans and Leases
Current	$ 984	$ 701
Total Accruing Loans and leases	984	701
Loans and Leases Receivable, Gross, Total	984	701
Leases, net
Age Analysis of Past Due Loans and Leases
Total past due	123	49
Current	705	1,286
Total Accruing Loans and leases	828	1,335
Loans and Leases Receivable, Gross, Total	$ 828	$ 1,335
Delinquency percentage	14.86%	3.67%
Real estate loans
Age Analysis of Past Due Loans and Leases
Loans and Leases Receivable, Gross, Total	$ 651,565	$ 577,945
Loans at fair value	11,278	11,422
Real estate loans \| Commercial mortgage
Age Analysis of Past Due Loans and Leases
Loans and Leases Receivable, Gross, Total	357,418	325,393
Real estate loans \| Home equity lines and loans
Age Analysis of Past Due Loans and Leases
Loans and Leases Receivable, Gross, Total	83,412	82,286
Real estate loans \| Residential mortgage
Age Analysis of Past Due Loans and Leases
Loans and Leases Receivable, Gross, Total	56,272	53,360
Loans at fair value	11,278	11,422
Real estate loans \| Construction
Age Analysis of Past Due Loans and Leases
Loans and Leases Receivable, Gross, Total	154,463	116,906
Current \| Real estate loans
Age Analysis of Past Due Loans and Leases
Loans at fair value	10,437	10,098
30-89 days past due
Age Analysis of Past Due Loans and Leases
Total past due	2,628	809
30-89 days past due \| Home equity lines and loans
Age Analysis of Past Due Loans and Leases
Total past due	592	348
30-89 days past due \| Residential mortgage
Age Analysis of Past Due Loans and Leases
Total past due		195
30-89 days past due \| Construction
Age Analysis of Past Due Loans and Leases
Total past due	1,519
30-89 days past due \| Commercial and industrial
Age Analysis of Past Due Loans and Leases
Total past due	394	217
30-89 days past due \| Leases, net
Age Analysis of Past Due Loans and Leases
Total past due	123	49
30-89 days past due \| Real estate loans
Age Analysis of Past Due Loans and Leases
Loans at fair value	0	187
Nonaccrual \| Real estate loans
Age Analysis of Past Due Loans and Leases
Loans at fair value	$ 841	$ 1,137

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