Changes in allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	$ 2,846	$ 2,646
Provision	236	208
Charge-offs	(19)	(9)
Recoveries		1
Ending balance	3,063	2,430
Residential 5+ multifamily
Financing Receivable, Past Due [Line Items]
Beginning balance	817	686
Provision	234	(64)
Charge-offs	(231)
Recoveries
Ending balance	820	622
Construction of residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	186	65
Provision	9	12
Charge-offs
Recoveries
Ending balance	195	77
Home equity lines of credit
Financing Receivable, Past Due [Line Items]
Beginning balance	198	252
Provision	2	(57)
Charge-offs	(2)
Recoveries
Ending balance	198	195
Residential real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	4,047	3,649
Provision	481	(317)
Charge-offs	(252)	(9)
Recoveries		1
Ending balance	4,276	3,324
Commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	5,416	6,546
Provision	(117)	530
Charge-offs	(103)	(6)
Recoveries		10
Ending balance	5,196	7,080
Construction of commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	1,025	596
Provision	114	(12)
Charge-offs
Recoveries
Ending balance	1,139	584
Commercial real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	6,441	7,142
Provision	(3)	518
Charge-offs	(103)	(6)
Recoveries		10
Ending balance	6,335	7,664
Farm land
Financing Receivable, Past Due [Line Items]
Beginning balance	21	59
Provision	(2)	(9)
Charge-offs
Recoveries
Ending balance	19	50
Vacant land
Financing Receivable, Past Due [Line Items]
Beginning balance	95	180
Provision	15	(71)
Charge-offs
Recoveries
Ending balance	110	109
Real estate secured
Financing Receivable, Past Due [Line Items]
Beginning balance	10,604	11,030
Provision	49	121
Charge-offs	(355)	(15)
Recoveries		11
Ending balance	10,740	11,147
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Beginning balance	1,364	1,397
Provision	(143)	(28)
Charge-offs	(46)
Recoveries	1
Ending balance	1,176	1,369
Municipal
Financing Receivable, Past Due [Line Items]
Beginning balance	31	43
Provision	(4)
Charge-offs
Recoveries
Ending balance	27	43
Consumer
Financing Receivable, Past Due [Line Items]
Beginning balance	82	77
Provision	33	(3)
Charge-offs	(15)	(24)
Recoveries	5	2
Ending balance	105	52
Unallocated
Financing Receivable, Past Due [Line Items]
Beginning balance	881	1,207
Provision	(14)	68
Charge-offs
Recoveries
Ending balance	867	1,275
Totals
Financing Receivable, Past Due [Line Items]
Beginning balance	12,962	13,754
Provision	363	158
Charge-offs	(416)	(39)
Recoveries	6	13
Ending balance	$ 12,915	$ 13,886