Changes in the allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	$ 2,430	$ 2,706	$ 2,646	$ 2,393
Provision	(55)	342	(264)	647
Charge-offs	(1)		(10)
Recoveries	3		5	8
Ending balance	2,377	3,048	2,377	3,048
Recoveries	(3)		(5)	(8)
Residential 5+ multifamily
Financing Receivable, Past Due [Line Items]
Beginning balance	622	508	686	446
Provision	(77)	122	(141)	185
Charge-offs		(41)		(42)
Recoveries
Ending balance	545	589	545	589
Recoveries
Construction of residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	77	87	65	75
Provision	18		30	12
Charge-offs
Recoveries
Ending balance	95	87	95	87
Recoveries
Home equity lines of credit
Financing Receivable, Past Due [Line Items]
Beginning balance	195	278	252	197
Provision	(5)	5	(62)	86
Charge-offs
Recoveries
Ending balance	190	283	190	283
Recoveries
Residential real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	3,324	3,579	3,649	3,111
Provision	(119)	469	(437)	930
Charge-offs	(1)	(41)	(10)	(42)
Recoveries	3		5	8
Ending balance	3,207	4,007	3,207	4,007
Recoveries	(3)		(5)	(8)
Commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	7,080	4,519	6,546	3,742
Provision	(875)	645	(345)	1,402
Charge-offs		(4)	(6)	(3)
Recoveries	7		17	19
Ending balance	6,212	5,160	6,212	5,160
Recoveries	(7)		(17)	(19)
Construction of commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	584	126	596	104
Provision	102	79	90	101
Charge-offs	(18)		(18)
Recoveries
Ending balance	668	205	668	205
Recoveries
Commercial real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	7,664	4,645	7,142	3,846
Provision	(773)	724	(255)	1,503
Charge-offs	(18)	(4)	(24)	(3)
Recoveries	7		17	19
Ending balance	6,880	5,365	6,880	5,365
Recoveries	(7)		(17)	(19)
Farm land
Financing Receivable, Past Due [Line Items]
Beginning balance	50	52	59	47
Provision	(18)	8	27	13
Charge-offs
Recoveries
Ending balance	32	60	32	60
Recoveries
Vacant land
Financing Receivable, Past Due [Line Items]
Beginning balance	109	144	180	71
Provision	(22)	38	(93)	111
Charge-offs
Recoveries
Ending balance	87	182	87	182
Recoveries
Real estate secured
Financing Receivable, Past Due [Line Items]
Beginning balance	11,147	8,420	11,030	7,075
Provision	(932)	1,239	(812)	2,557
Charge-offs	(19)	(45)	(34)	(45)
Recoveries	10		22	27
Ending balance	10,206	9,614	10,206	9,614
Recoveries	(10)		(22)	(27)
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Beginning balance	1,369	1,071	1,397	1,145
Provision	(27)	444	(55)	370
Charge-offs	(131)		(131)
Recoveries	45		45
Ending balance	1,256	1,515	1,256	1,515
Recoveries	(45)		(45)
Municipal
Financing Receivable, Past Due [Line Items]
Beginning balance	43	53	43	46
Provision	(11)	(17)	(11)	(10)
Charge-offs
Recoveries
Ending balance	32	36	32	36
Recoveries
Consumer
Financing Receivable, Past Due [Line Items]
Beginning balance	52	102	77	60
Provision	22	(20)	20	32
Charge-offs	(11)	(13)	(15)	(25)
Recoveries	3	5	16	7
Ending balance	66	74	66	74
Recoveries	(3)	(5)	(16)	(7)
Unallocated
Financing Receivable, Past Due [Line Items]
Beginning balance	1,275	972	1,207	569
Provision	(127)	160	(59)	563
Charge-offs
Recoveries
Ending balance	1,148	1,132	1,148	1,132
Recoveries
Totals
Financing Receivable, Past Due [Line Items]
Beginning balance	13,886	10,618	13,754	8,895
Provision	(1,075)	1,806	(917)	3,512
Charge-offs	(161)	(58)	(180)	(70)
Recoveries	58	5	51	34
Ending balance	12,708	12,371	12,708	12,371
Recoveries	$ (58)	$ (5)	$ (51)	$ (34)