Loans, net and allowance for credit losses - Major Classification of Loans Portfolio Summarized by Credit Quality (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable
2023	$ 93,492
2022	721,516
2021	714,562
2020	233,654
2019	228,244
Prior	605,139
Revolving Loans Amortized Cost Basis	221,436
Total	2,818,043
Loans	2,818,043	$ 2,730,116
Gross charge-offs, 2022	1
Gross charge-offs, 2021	35
Gross charge-offs, 2020	17
Gross charge-offs, 2019	10
Gross charge-offs, Prior	8
Gross charge-offs, Revolving Loans Amortized Cost Basis	4
Total	75
Commercial
Accounts, Notes, Loans and Financing Receivable
2023	11,546
2022	50,495
2021	46,399
2020	32,496
2019	50,313
Prior	90,214
Revolving Loans Amortized Cost Basis	148,635
Total	430,098
Loans	430,098	433,048
Gross charge-offs, Revolving Loans Amortized Cost Basis	4
Total	4
Municipal
Accounts, Notes, Loans and Financing Receivable
2023	1,400
2022	45,146
2021	91,776
2020	11,850
2019	36
Prior	18,983
Revolving Loans Amortized Cost Basis	87
Total	169,278
Loans	169,278	166,210
Commercial real estate
Accounts, Notes, Loans and Financing Receivable
2023	57,257
2022	531,819
2021	490,161
2020	152,010
2019	154,933
Prior	396,731
Total	1,782,911
Loans	1,782,911	1,709,827
Residential real estate
Accounts, Notes, Loans and Financing Receivable
2023	5,741
2022	55,051
2021	69,028
2020	29,141
2019	17,764
Prior	93,720
Revolving Loans Amortized Cost Basis	72,014
Total	342,459
Loans	342,459	330,728
Consumer
Accounts, Notes, Loans and Financing Receivable
2023	17,548
2022	39,005
2021	17,198
2020	8,157
2019	5,198
Prior	5,491
Revolving Loans Amortized Cost Basis	700
Total	93,297
Loans	93,297	90,303
Gross charge-offs, 2022	1
Gross charge-offs, 2021	35
Gross charge-offs, 2020	17
Gross charge-offs, 2019	10
Gross charge-offs, Prior	8
Total	71
Pass
Accounts, Notes, Loans and Financing Receivable
Loans		2,708,780
Pass | Commercial
Accounts, Notes, Loans and Financing Receivable
2023	11,531
2022	50,495
2021	46,353
2020	32,496
2019	50,260
Prior	89,938
Revolving Loans Amortized Cost Basis	140,615
Total	421,688
Loans		424,411
Pass | Municipal
Accounts, Notes, Loans and Financing Receivable
2023	1,400
2022	45,146
2021	91,776
2020	11,850
2019	36
Prior	18,983
Revolving Loans Amortized Cost Basis	87
Total	169,278
Loans		166,210
Pass | Commercial real estate
Accounts, Notes, Loans and Financing Receivable
2023	55,319
2022	531,819
2021	488,524
2020	151,845
2019	154,002
Prior	386,268
Total	1,767,777
Loans		1,699,041
Pass | Residential real estate
Accounts, Notes, Loans and Financing Receivable
2023	5,741
2022	55,051
2021	69,011
2020	28,927
2019	17,764
Prior	93,343
Revolving Loans Amortized Cost Basis	72,014
Total	341,851
Loans		329,098
Pass | Consumer
Accounts, Notes, Loans and Financing Receivable
2023	17,548
2022	39,005
2021	17,087
2020	8,127
2019	5,179
Prior	5,457
Revolving Loans Amortized Cost Basis	700
Total	93,103
Loans		90,020
Special Mention
Accounts, Notes, Loans and Financing Receivable
Loans		15,331
Special Mention | Commercial
Accounts, Notes, Loans and Financing Receivable
Revolving Loans Amortized Cost Basis	67
Total	67
Loans		7,822
Special Mention | Commercial real estate
Accounts, Notes, Loans and Financing Receivable
2023	1,763
2019	303
Prior	3,301
Total	5,367
Loans		7,509
Substandard
Accounts, Notes, Loans and Financing Receivable
Loans		6,005
Substandard | Commercial
Accounts, Notes, Loans and Financing Receivable
2023	15
2021	46
2019	53
Prior	276
Revolving Loans Amortized Cost Basis	7,953
Total	8,343
Loans		815
Substandard | Commercial real estate
Accounts, Notes, Loans and Financing Receivable
2023	175
2021	1,637
2020	165
2019	628
Prior	7,162
Total	9,767
Loans		3,277
Substandard | Residential real estate
Accounts, Notes, Loans and Financing Receivable
2021	17
2020	214
Prior	377
Total	608
Loans		1,630
Substandard | Consumer
Accounts, Notes, Loans and Financing Receivable
2021	111
2020	30
2019	19
Prior	34
Total	$ 194
Loans		$ 283