activity within the allowance for loan losses by loan segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	$ 2,393	$ 2,149	$ 1,862
Provision	255	367	580
Charge-offs	(11)	(136)	(299)
Recoveries	9	3	6
Ending balance	2,646	2,393	2,149
Acquisition Discount Transfer		10
Residential 5+ multifamily
Financing Receivable, Past Due [Line Items]
Beginning balance	446	413	155
Provision	282	33	258
Charge-offs	(42)
Recoveries
Ending balance	686	446	413
Acquisition Discount Transfer
Construction of residential 1-4 family
Financing Receivable, Past Due [Line Items]
Beginning balance	75	83	75
Provision	(10)	(8)	8
Charge-offs
Recoveries
Ending balance	65	75	83
Acquisition Discount Transfer
Home equity lines of credit
Financing Receivable, Past Due [Line Items]
Beginning balance	197	219	236
Provision	(197)	258	(18)
Charge-offs		(281)
Recoveries	252		1
Ending balance	252	197	219
Acquisition Discount Transfer		1
Residential real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	3,111	2,864	2,328
Provision	330	650	828
Charge-offs	(53)	(417)	(299)
Recoveries	261	3	7
Ending balance	3,649	3,111	2,864
Acquisition Discount Transfer		11
Commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	3,742	3,048	2,547
Provision	2,776	248	756
Charge-offs	(17)	(44)	(259)
Recoveries	45	2	4
Ending balance	6,546	3,742	3,048
Acquisition Discount Transfer		488
Construction of commercial
Financing Receivable, Past Due [Line Items]
Beginning balance	104	122	80
Provision	492	(18)	42
Charge-offs
Recoveries
Ending balance	596	104	122
Acquisition Discount Transfer
Commercial real estate
Financing Receivable, Past Due [Line Items]
Beginning balance	3,846	3,170	2,627
Provision	3,268	230	798
Charge-offs	(17)	(44)	(259)
Recoveries	45	2	4
Ending balance	7,142	3,846	3,170
Acquisition Discount Transfer		488
Farm land
Financing Receivable, Past Due [Line Items]
Beginning balance	47	33	32
Provision	12	14	(6)
Charge-offs
Recoveries			7
Ending balance	59	47	33
Acquisition Discount Transfer
Vacant land
Financing Receivable, Past Due [Line Items]
Beginning balance	71	100	132
Provision	109	(29)	(32)
Charge-offs
Recoveries
Ending balance	180	71	100
Acquisition Discount Transfer
Real estate secured
Financing Receivable, Past Due [Line Items]
Beginning balance	7,075	6,167	5,119
Provision	3,719	865	1,588
Charge-offs	(70)	(461)	(558)
Recoveries	306	5	18
Ending balance	11,030	7,075	6,167
Acquisition Discount Transfer		499
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Beginning balance	1,145	1,158	984
Provision	612	(78)	255
Charge-offs	(362)	(145)	(108)
Recoveries	2	46	27
Ending balance	1,397	1,145	1,158
Acquisition Discount Transfer		164
Municipal
Financing Receivable, Past Due [Line Items]
Beginning balance	46	12	30
Provision	(3)	34	(18)
Charge-offs
Recoveries
Ending balance	43	46	12
Acquisition Discount Transfer
Consumer
Financing Receivable, Past Due [Line Items]
Beginning balance	60	56	80
Provision	72	3	28
Charge-offs	(70)	(36)	(81)
Recoveries	15	37	29
Ending balance	77	60	56
Acquisition Discount Transfer
Unallocated
Financing Receivable, Past Due [Line Items]
Beginning balance	569	438	563
Provision	638	131	(125)
Charge-offs
Recoveries
Ending balance	1,207	569	438
Acquisition Discount Transfer
Totals
Financing Receivable, Past Due [Line Items]
Beginning balance	8,895	7,831	6,776
Provision	5,038	955	1,728
Charge-offs	(502)	(642)	(747)
Recoveries	323	88	74
Ending balance	$ 13,754	8,895	$ 7,831
Acquisition Discount Transfer		$ 663