Changes in allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Residential 1-4 family
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	$ 3,286	$ 2,377	$ 2,846	$ 2,646
Allowance for Loan and Lease Losses, Period Increase (Decrease)	127	393	595	129
Allowance for Loan and Lease Losses, Write-offs	45	35	73	44
Allowance for Loan and Lease Loss, Recovery of Bad Debts	25	5	25	9
Loans and Leases Receivable, Allowance	3,393	2,740	3,393	2,740
Allowance for Loan and Lease Loss, Recovery of Bad Debts	(25)	(5)	(25)	(9)
Residential 5+ multifamily
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	1,157	545	817	686
Allowance for Loan and Lease Losses, Period Increase (Decrease)	71	156	642	15
Allowance for Loan and Lease Losses, Write-offs			(231)
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	1,228	701	1,228	701
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Construction of residential 1-4 family
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	333	95	186	65
Allowance for Loan and Lease Losses, Period Increase (Decrease)	(103)	41	44	71
Allowance for Loan and Lease Losses, Write-offs	(25)		(25)
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	205	136	205	136
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Home equity lines of credit
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	205	190	198	252
Allowance for Loan and Lease Losses, Period Increase (Decrease)	14	26	32	(36)
Allowance for Loan and Lease Losses, Write-offs		(20)	(11)	(20)
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	219	196	219	196
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Residential real estate
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	4,981	3,207	4,047	3,649
Allowance for Loan and Lease Losses, Period Increase (Decrease)	109	616	1,313	179
Allowance for Loan and Lease Losses, Write-offs	(70)	(55)	(340)	(64)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	25	5	25	9
Loans and Leases Receivable, Allowance	5,045	3,773	5,045	3,773
Allowance for Loan and Lease Loss, Recovery of Bad Debts	(25)	(5)	(25)	(9)
Commercial
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	5,169	6,212	5,416	6,546
Allowance for Loan and Lease Losses, Period Increase (Decrease)	598	(165)	722	(509)
Allowance for Loan and Lease Losses, Write-offs			(372)	(7)
Allowance for Loan and Lease Loss, Recovery of Bad Debts		119	1	136
Loans and Leases Receivable, Allowance	5,767	6,166	5,767	6,166
Allowance for Loan and Lease Loss, Recovery of Bad Debts		(119)	(1)	(136)
Construction of commercial
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	872	668	1,025	596
Allowance for Loan and Lease Losses, Period Increase (Decrease)	(115)	118	(268)	208
Allowance for Loan and Lease Losses, Write-offs				(18)
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	757	786	757	786
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Commercial real estate
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	6,041	6,880	6,441	7,142
Allowance for Loan and Lease Losses, Period Increase (Decrease)	483	(47)	454	(301)
Allowance for Loan and Lease Losses, Write-offs			(372)	(25)
Allowance for Loan and Lease Loss, Recovery of Bad Debts		119	1	136
Loans and Leases Receivable, Allowance	6,524	6,952	6,524	6,952
Allowance for Loan and Lease Loss, Recovery of Bad Debts		(119)	(1)	(136)
Farm land
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	27	32	21	59
Allowance for Loan and Lease Losses, Period Increase (Decrease)	11	(1)	17	(28)
Allowance for Loan and Lease Losses, Write-offs
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	38	31	38	31
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Vacant land
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	108	87	95	180
Allowance for Loan and Lease Losses, Period Increase (Decrease)	4	(1)	17	(94)
Allowance for Loan and Lease Losses, Write-offs
Allowance for Loan and Lease Loss, Recovery of Bad Debts				1
Loans and Leases Receivable, Allowance	112	87	112	87
Allowance for Loan and Lease Loss, Recovery of Bad Debts				(1)
Real estate secured
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	11,157	10,206	10,604	11,030
Allowance for Loan and Lease Losses, Period Increase (Decrease)	607	567	1,801	(244)
Allowance for Loan and Lease Losses, Write-offs	(70)	(55)	(712)	(89)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	25	125	26	146
Loans and Leases Receivable, Allowance	11,719	10,843	11,719	10,843
Allowance for Loan and Lease Loss, Recovery of Bad Debts	(25)	(125)	(26)	(146)
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	1,480	1,256	1,364	1,397
Allowance for Loan and Lease Losses, Period Increase (Decrease)	5	73	166	17
Allowance for Loan and Lease Losses, Write-offs			(46)	(131)
Allowance for Loan and Lease Loss, Recovery of Bad Debts		3	1	49
Loans and Leases Receivable, Allowance	1,485	1,332	1,485	1,332
Allowance for Loan and Lease Loss, Recovery of Bad Debts		(3)	(1)	(49)
Municipal
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	35	32	31	43
Allowance for Loan and Lease Losses, Period Increase (Decrease)	4	(1)	8	(12)
Allowance for Loan and Lease Losses, Write-offs
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	39	31	39	31
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Consumer
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	130	66	82	77
Allowance for Loan and Lease Losses, Period Increase (Decrease)	11	62	95	82
Allowance for Loan and Lease Losses, Write-offs	(25)	(19)	(70)	(34)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	6	6	15	10
Loans and Leases Receivable, Allowance	122	115	122	115
Allowance for Loan and Lease Loss, Recovery of Bad Debts	(6)	(6)	(15)	(10)
Unallocated
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	901	1,148	881	1,207
Allowance for Loan and Lease Losses, Period Increase (Decrease)	68	(301)	88	(360)
Allowance for Loan and Lease Losses, Write-offs
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Loans and Leases Receivable, Allowance	969	847	969	847
Allowance for Loan and Lease Loss, Recovery of Bad Debts
Totals
Financing Receivable, Past Due [Line Items]
Loans and Leases Receivable, Allowance	13,703	12,708	12,962	13,754
Allowance for Loan and Lease Losses, Period Increase (Decrease)	695	400	2,158	517
Allowance for Loan and Lease Losses, Write-offs	(95)	74	828	254
Allowance for Loan and Lease Loss, Recovery of Bad Debts	31	134	42	185
Loans and Leases Receivable, Allowance	14,334	13,168	14,334	13,168
Allowance for Loan and Lease Loss, Recovery of Bad Debts	$ (31)	$ (134)	$ (42)	$ (185)