Changes in allowance for loan losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Beginning balance	$ 13,754
Ending balance	12,962	$ 13,754
Residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	2,646	2,393	$ 2,149
Provision	225	255	367
Charge-offs	(44)	(11)	(136)
Recoveries	19	9	3
Ending balance	2,846	2,646	2,393
Recoveries	(19)	(9)	(3)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			10
Residential 5+ multifamily
Financing Receivable, Past Due [Line Items]
Beginning balance	686	446	413
Provision	131	282	33
Charge-offs		(42)
Recoveries
Ending balance	817	686	446
Recoveries
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Construction of residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	65	75	83
Provision	121	(10)	(8)
Charge-offs
Recoveries
Ending balance	186	65	75
Recoveries
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Home equity lines of credit
Financing Receivable, Past Due [Line Items]
Beginning balance	252	197	219
Provision	(34)	(197)	258
Charge-offs	(21)		(281)
Recoveries	1	252
Ending balance	198	252	197
Recoveries	(1)	(252)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			1
Residential real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	3,649	3,111	2,864
Provision	443	330	650
Charge-offs	(65)	(53)	(417)
Recoveries	20	261	3
Ending balance	4,047	3,649	3,111
Recoveries	(20)	(261)	(3)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			11
Commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	6,546	3,742	3,048
Provision	(1,260)	2,776	248
Charge-offs	(6)	(17)	(44)
Recoveries	136	45	2
Ending balance	5,416	6,546	3,742
Recoveries	(136)	(45)	(2)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			488
Construction of commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	596	104	122
Provision	447	492	(18)
Charge-offs	(18)
Recoveries
Ending balance	1,025	596	104
Recoveries
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Commercial real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	7,142	3,846	3,170
Provision	(813)	3,268	230
Charge-offs	(24)	(17)	(44)
Recoveries	136	45	2
Ending balance	6,441	7,142	3,846
Recoveries	(136)	(45)	(2)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			488
Farm land
Financing Receivable, Past Due [Line Items]
Beginning balance	59	47	33
Provision	(39)	12	14
Charge-offs	(2)
Recoveries	3
Ending balance	21	59	47
Recoveries	(3)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Vacant land
Financing Receivable, Past Due [Line Items]
Beginning balance	180	71	100
Provision	(86)	109	(29)
Charge-offs
Recoveries	1
Ending balance	95	180	71
Recoveries	(1)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Real estate secured
Financing Receivable, Past Due [Line Items]
Beginning balance	11,030	7,075	6,167
Provision	(495)	3,719	865
Charge-offs	(91)	(70)	(461)
Recoveries	160	306	5
Ending balance	10,604	11,030	7,075
Recoveries	(160)	(306)	(5)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			499
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Beginning balance	1,397	1,145	1,158
Provision	45	612	(78)
Charge-offs	(131)	(362)	(145)
Recoveries	53	2	46
Ending balance	1,364	1,397	1,145
Recoveries	(53)	(2)	(46)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			164
Municipal
Financing Receivable, Past Due [Line Items]
Beginning balance	43	46	12
Provision	(12)	(3)	34
Charge-offs
Recoveries
Ending balance	31	43	46
Recoveries
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Consumer
Financing Receivable, Past Due [Line Items]
Beginning balance	77	60	56
Provision	68	72	3
Charge-offs	(59)	(70)	(36)
Recoveries	4	15	37
Ending balance	82	77	60
Recoveries	(4)	(15)	(37)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Unallocated
Financing Receivable, Past Due [Line Items]
Beginning balance	1,207	569	438
Provision	(326)	638	131
Charge-offs
Recoveries
Ending balance	881	1,207	569
Recoveries
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]
Totals
Financing Receivable, Past Due [Line Items]
Beginning balance	13,754	8,895	7,831
Provision	(720)	5,038	955
Charge-offs	(281)	(502)	(642)
Recoveries	209	323	88
Ending balance	12,962	13,754	8,895
Recoveries	$ (209)	$ (323)	(88)
[custom:AllowanceForLoanLossesAcquisitionDiscountTransfer]			$ 663