Loans - Risk by loan portfolio (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Total loans			$ 2,106,559
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	$ 2,167,367	$ 2,167,367
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Total loans	1,125
SBA 504 loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			35,077
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	31,657	31,657
SBA loans held for investment
Financing Receivable, Recorded Investment [Line Items]
Total loans			38,468
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	979	979
2022	8,700	8,700
2021	7,369	7,369
2020	6,949	6,949
2019	2,704	2,704
2018 and Earlier	13,177	13,177
Total Loans	39,878	39,878
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2019		113
Total loans		113
SBA and commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			1,231,919
SBA PPP loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			5,908
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2021	2,555	2,555
Total Loans	2,555	2,555
Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			1,187,543
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	84,290	84,290
2022	345,584	345,584
2021	187,828	187,828
2020	138,307	138,307
2019	105,599	105,599
2018 and Earlier	300,717	300,717
Revolving Loans Amortized Cost Basis	93,707	93,707
Total Loans	1,256,032	1,256,032
Commercial loans | SBA 504 loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			35,077
Commercial loans | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans			903,126
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	931,756	931,756
Commercial loans | Commercial real estate construction
Financing Receivable, Recorded Investment [Line Items]
Total loans			131,774
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	161,882	161,882
Commercial loans | Consumer other
Financing Receivable, Recorded Investment [Line Items]
Total loans			117,566
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	130,737	130,737
Residential mortgage loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			605,091
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	71,216	71,216
2022	268,961	268,961
2021	79,593	79,593
2020	55,652	55,652
2019	34,570	34,570
2018 and Earlier	123,422	123,422
Total Loans	633,414	633,414
Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			78,164
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1,562	1,562
2022	5,438	5,438
2021	5,650	5,650
2020	724	724
2019	3,399	3,399
2018 and Earlier	8,321	8,321
Revolving Loans Amortized Cost Basis	50,896	50,896
Total Loans	75,990	75,990
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2021		345
Total loans	225	345
Consumer loans | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total loans			68,310
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	68,379	68,379
Consumer loans | Consumer other
Financing Receivable, Recorded Investment [Line Items]
Total loans			9,854
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total Loans	7,611	7,611
Residential construction loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			163,457
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	13,093	13,093
2022	76,151	76,151
2021	37,867	37,867
2020	7,751	7,751
2019	500	500
2018 and Earlier	3,027	3,027
Revolving Loans Amortized Cost Basis	1,035	1,035
Total Loans	139,424	139,424
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
2018 and Earlier		500
Revolving Loans Amortized Cost Basis		400
Total loans	900	900
Total
Financing Receivable, Recorded Investment [Line Items]
Total loans			2,078,631
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	171,140	171,140
2022	704,834	704,834
2021	320,862	320,862
2020	209,383	209,383
2019	146,772	146,772
2018 and Earlier	448,664	448,664
Revolving Loans Amortized Cost Basis	145,638	145,638
Total Loans	2,147,293	2,147,293
Residential mortgage, consumer and residential construction loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			846,712
Performing | Residential mortgage loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			601,730
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	69,505	69,505
2022	266,630	266,630
2021	77,180	77,180
2020	54,857	54,857
2019	34,294	34,294
2018 and Earlier	122,341	122,341
Total Loans	624,807	624,807
Performing | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			78,164
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1,562	1,562
2022	5,438	5,438
2021	5,650	5,650
2020	724	724
2019	3,399	3,399
2018 and Earlier	8,321	8,321
Revolving Loans Amortized Cost Basis	50,626	50,626
Total Loans	75,720	75,720
Performing | Consumer loans | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total loans			68,310
Performing | Consumer loans | Consumer other
Financing Receivable, Recorded Investment [Line Items]
Total loans			9,854
Performing | Residential construction loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			160,025
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	13,093	13,093
2022	76,151	76,151
2021	37,515	37,515
2020	7,751	7,751
2019	500	500
2018 and Earlier	1,232	1,232
Total Loans	136,242	136,242
Performing | Residential mortgage, consumer and residential construction loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			839,919
Nonperforming | Residential mortgage loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			3,361
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1,711	1,711
2022	2,331	2,331
2021	2,413	2,413
2020	795	795
2019	276	276
2018 and Earlier	1,081	1,081
Total Loans	8,607	8,607
Nonperforming | Consumer loans
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Revolving Loans Amortized Cost Basis	270	270
Total Loans	270	270
Nonperforming | Residential construction loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			3,432
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2021	352	352
2018 and Earlier	1,795	1,795
Revolving Loans Amortized Cost Basis	1,035	1,035
Total Loans	3,182	3,182
Nonperforming | Residential mortgage, consumer and residential construction loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			6,793
Pass | SBA loans held for investment
Financing Receivable, Recorded Investment [Line Items]
Total loans			37,163
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	979	979
2022	7,339	7,339
2021	5,132	5,132
2020	6,247	6,247
2019	2,704	2,704
2018 and Earlier	11,627	11,627
Total Loans	34,028	34,028
Pass | SBA and commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			1,214,139
Pass | SBA PPP loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			5,908
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2021	2,555	2,555
Total Loans	2,555	2,555
Pass | Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			1,171,068
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	84,290	84,290
2022	345,498	345,498
2021	185,728	185,728
2020	138,087	138,087
2019	103,348	103,348
2018 and Earlier	286,754	286,754
Revolving Loans Amortized Cost Basis	93,312	93,312
Total Loans	1,237,017	1,237,017
Pass | Commercial loans | SBA 504 loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			35,077
Pass | Commercial loans | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans			894,110
Pass | Commercial loans | Commercial real estate construction
Financing Receivable, Recorded Investment [Line Items]
Total loans			131,774
Pass | Commercial loans | Consumer other
Financing Receivable, Recorded Investment [Line Items]
Total loans			110,107
Special mention | SBA loans held for investment
Financing Receivable, Recorded Investment [Line Items]
Total loans			558
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2020	702	702
2018 and Earlier	758	758
Total Loans	1,460	1,460
Special mention | SBA and commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			13,006
Special mention | Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			12,448
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2022	86	86
2021	2,100	2,100
2019	2,251	2,251
2018 and Earlier	11,386	11,386
Revolving Loans Amortized Cost Basis	395	395
Total Loans	16,218	16,218
Special mention | Commercial loans | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans			6,228
Special mention | Commercial loans | Consumer other
Financing Receivable, Recorded Investment [Line Items]
Total loans			6,220
Substandard | SBA loans held for investment
Financing Receivable, Recorded Investment [Line Items]
Total loans			747
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2022	1,361	1,361
2021	2,237	2,237
2018 and Earlier	792	792
Total Loans	4,390	4,390
Substandard | SBA and commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			4,774
Substandard | Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Total loans			4,027
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2020	220	220
2018 and Earlier	2,577	2,577
Total Loans	$ 2,797	$ 2,797
Substandard | Commercial loans | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans			2,788
Substandard | Commercial loans | Consumer other
Financing Receivable, Recorded Investment [Line Items]
Total loans			$ 1,239