Loans and allowance for loan losses - Information on the risk rating of loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 527,556	$ 526,457	$ 526,457
Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,758		3,003
Risk Rated 1-4
Financing Receivable, Recorded Investment [Line Items]
Total loans	509,767	490,480
Risk Rated 5
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,779	30,644
Risk Rated 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,010	5,333
Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total loans	37,028	49,149	49,149
Construction and land development | Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,026	6,805	6,805
Construction and land development | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	30,002	42,344	42,344
Construction and land development | Risk Rated 1-4
Financing Receivable, Recorded Investment [Line Items]
Total loans	34,391	46,512
Construction and land development | Risk Rated 1-4 | Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,026	6,805
Construction and land development | Risk Rated 1-4 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	27,365	39,707
Construction and land development | Risk Rated 5
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,637	2,637
Construction and land development | Risk Rated 5 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,637	2,637
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	294,269	255,537	255,537
Commercial real estate | Owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	124,496	113,108	113,108
Commercial real estate | Non-owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	151,738	129,786	129,786
Commercial real estate | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,119	11,666	11,666
Commercial real estate | Farmland
Financing Receivable, Recorded Investment [Line Items]
Total loans	916	977	977
Commercial real estate | Risk Rated 1-4
Financing Receivable, Recorded Investment [Line Items]
Total loans	283,127	230,181
Commercial real estate | Risk Rated 1-4 | Owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	119,080	103,370
Commercial real estate | Risk Rated 1-4 | Non-owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	146,012	114,168
Commercial real estate | Risk Rated 1-4 | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,119	11,666
Commercial real estate | Risk Rated 1-4 | Farmland
Financing Receivable, Recorded Investment [Line Items]
Total loans	916	977
Commercial real estate | Risk Rated 5
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,330	21,513
Commercial real estate | Risk Rated 5 | Owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,884	6,181
Commercial real estate | Risk Rated 5 | Non-owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,446	15,332
Commercial real estate | Risk Rated 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,812	3,843
Commercial real estate | Risk Rated 6 | Owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,532	3,557
Commercial real estate | Risk Rated 6 | Non-owner occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	280	286
Consumer real estate secured by 1-4 family residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	83,969	92,372	92,372
Consumer real estate secured by 1-4 family residential | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,938	17,977	17,977
Consumer real estate secured by 1-4 family residential | First deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	58,378	62,277	62,277
Consumer real estate secured by 1-4 family residential | Second deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,653	12,118	12,118
Consumer real estate secured by 1-4 family residential | Risk Rated 1-4
Financing Receivable, Recorded Investment [Line Items]
Total loans	81,627	86,478
Consumer real estate secured by 1-4 family residential | Risk Rated 1-4 | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,016	17,054
Consumer real estate secured by 1-4 family residential | Risk Rated 1-4 | First deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	57,319	57,932
Consumer real estate secured by 1-4 family residential | Risk Rated 1-4 | Second deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,292	11,492
Consumer real estate secured by 1-4 family residential | Risk Rated 5
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,233	4,657
Consumer real estate secured by 1-4 family residential | Risk Rated 5 | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	622	623
Consumer real estate secured by 1-4 family residential | Risk Rated 5 | First deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	526	3,605
Consumer real estate secured by 1-4 family residential | Risk Rated 5 | Second deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	85	429
Consumer real estate secured by 1-4 family residential | Risk Rated 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,109	1,237
Consumer real estate secured by 1-4 family residential | Risk Rated 6 | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	300	300
Consumer real estate secured by 1-4 family residential | Risk Rated 6 | First deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	533	740
Consumer real estate secured by 1-4 family residential | Risk Rated 6 | Second deed of trust
Financing Receivable, Recorded Investment [Line Items]
Total loans	276	197
Commercial and industrial loans | Commercial and industrial loans (except those secured by real estate)
Financing Receivable, Recorded Investment [Line Items]
Total loans	85,119	100,421	100,421
Commercial and industrial loans | Guaranteed student loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,413	25,975	$ 25,975
Commercial and industrial loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,758	3,003
Commercial and industrial loans | Risk Rated 1-4 | Commercial and industrial loans (except those secured by real estate)
Financing Receivable, Recorded Investment [Line Items]
Total loans	83,477	98,362
Commercial and industrial loans | Risk Rated 1-4 | Guaranteed student loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,413	25,975
Commercial and industrial loans | Risk Rated 1-4 | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,732	2,972
Commercial and industrial loans | Risk Rated 5 | Commercial and industrial loans (except those secured by real estate)
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,553	1,806
Commercial and industrial loans | Risk Rated 5 | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Total loans	26	31
Commercial and industrial loans | Risk Rated 6 | Commercial and industrial loans (except those secured by real estate)
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 89	$ 253