Changes in the allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	$ 2,377	$ 3,048	$ 2,646	$ 2,393
Provision	393	69	129	716
Charge-offs	(35)	(11)	(44)	(11)
Recoveries	5	1	9	9
Ending balance	2,740	3,107	2,740	3,107
Recoveries	(5)	(1)	(9)	(9)
Residential 5+ multifamily
Financing Receivable, Past Due [Line Items]
Beginning balance	545	589	686	446
Provision	156	14	15	199
Charge-offs				(42)
Recoveries
Ending balance	701	603	701	603
Recoveries
Construction of residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	95	87	65	75
Provision	41	10	71	22
Charge-offs
Recoveries
Ending balance	136	97	136	97
Recoveries
Home equity lines of credit
Financing Receivable, Past Due [Line Items]
Beginning balance	190	283	252	197
Provision	26	(8)	(36)	78
Charge-offs	(20)		(20)
Recoveries
Ending balance	196	275	196	275
Recoveries
Residential real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	3,207	4,007	3,649	3,111
Provision	616	85	179	1,015
Charge-offs	(55)	(11)	(64)	(53)
Recoveries	5	1	9	9
Ending balance	3,773	4,082	3,773	4,082
Recoveries	(5)	(1)	(9)	(9)
Commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	6,212	5,160	6,546	3,742
Provision	(165)	317	(509)	1,719
Charge-offs		(14)	(7)	(17)
Recoveries	119	1	136	20
Ending balance	6,166	5,464	6,166	5,464
Recoveries	(119)	(1)	(136)	(20)
Construction of commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	668	205	596	104
Provision	118	195	208	296
Charge-offs			(18)
Recoveries
Ending balance	786	400	786	400
Recoveries
Commercial real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	6,880	5,365	7,142	3,846
Provision	(47)	512	(301)	2,015
Charge-offs		(14)	(25)	(17)
Recoveries	119	1	136	20
Ending balance	6,952	5,864	6,952	5,864
Recoveries	(119)	(1)	(136)	(20)
Farm land
Financing Receivable, Past Due [Line Items]
Beginning balance	32	60	59	47
Provision	(1)	5	28	18
Charge-offs
Recoveries
Ending balance	31	65	31	65
Recoveries
Vacant land
Financing Receivable, Past Due [Line Items]
Beginning balance	87	182	180	71
Provision	(1)	(11)	(94)	100
Charge-offs
Recoveries	1		1
Ending balance	87	171	87	171
Recoveries	(1)		(1)
Real estate secured
Financing Receivable, Past Due [Line Items]
Beginning balance	10,206	9,614	11,030	7,075
Provision	567	591	(244)	3,148
Charge-offs	(55)	(25)	(89)	(70)
Recoveries	125	2	146	29
Ending balance	10,843	10,182	10,843	10,182
Recoveries	(125)	(2)	(146)	(29)
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Beginning balance	1,256	1,515	1,397	1,145
Provision	73	(44)	17	326
Charge-offs			(131)
Recoveries	3	1	49	1
Ending balance	1,332	1,472	1,332	1,472
Recoveries	(3)	(1)	(49)	(1)
Municipal
Financing Receivable, Past Due [Line Items]
Beginning balance	32	36	43	46
Provision	(1)	5	(12)	(5)
Charge-offs
Recoveries
Ending balance	31	41	31	41
Recoveries
Consumer
Financing Receivable, Past Due [Line Items]
Beginning balance	66	74	77	60
Provision	62	40	82	72
Charge-offs	(19)	(41)	(34)	(66)
Recoveries	6	7	10	14
Ending balance	115	80	115	80
Recoveries	(6)	(7)	(10)	(14)
Unallocated
Financing Receivable, Past Due [Line Items]
Beginning balance	1,148	1,132	1,207	569
Provision	(301)	94	(360)	657
Charge-offs
Recoveries
Ending balance	847	1,226	847	1,226
Recoveries
Totals
Financing Receivable, Past Due [Line Items]
Beginning balance	12,708	12,371	13,754	8,895
Provision	400	686	(517)	4,198
Charge-offs	(74)	(66)	(254)	(136)
Recoveries	134	10	185	44
Ending balance	13,168	13,001	13,168	13,001
Recoveries	$ (134)	$ (10)	$ (185)	$ (44)