Loans and allowance for loan losses - Aging of recorded investment in past due loans and leases (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 527,556	$ 526,457	$ 526,457
Total Loans	527,556	526,457
Recorded Investment, 90 Days and Accruing	1,638	1,961
Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	523,359	521,718
Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	4,197	4,739
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,606	1,987
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	953	791
Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,638	1,961
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,758		3,003
Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	37,028	49,149	49,149
Total Loans	37,028	49,149
Construction and land development | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	37,028	49,149
Construction and land development | Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7,026	6,805	6,805
Total Loans	7,026	6,805
Construction and land development | Residential | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7,026	6,805
Construction and land development | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	30,002	42,344	42,344
Total Loans	30,002	42,344
Construction and land development | Commercial | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	30,002	42,344
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	294,269	255,537	255,537
Total Loans	294,269	255,537
Commercial real estate | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	294,269	255,537
Commercial real estate | Owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	124,496	113,108	113,108
Total Loans	124,496	113,108
Commercial real estate | Owner occupied | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	124,496	113,108
Commercial real estate | Non-owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	151,738	129,786	129,786
Total Loans	151,738	129,786
Commercial real estate | Non-owner occupied | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	151,738	129,786
Commercial real estate | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	17,119	11,666	11,666
Total Loans	17,119	11,666
Commercial real estate | Multifamily | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	17,119	11,666
Commercial real estate | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	916	977	977
Total Loans	916	977
Commercial real estate | Farmland | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	916	977
Consumer real estate secured by 1-4 family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	83,969	92,372	92,372
Total Loans	83,969	92,372
Consumer real estate secured by 1-4 family residential | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	83,921	92,372
Consumer real estate secured by 1-4 family residential | Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	48
Consumer real estate secured by 1-4 family residential | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	42
Consumer real estate secured by 1-4 family residential | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6
Consumer real estate secured by 1-4 family residential | Home equity lines
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	19,938	17,977	17,977
Total Loans	19,938	17,977
Consumer real estate secured by 1-4 family residential | Home equity lines | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	19,938	17,977
Consumer real estate secured by 1-4 family residential | First deed of trust
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	58,378	62,277	62,277
Total Loans	58,378	62,277
Consumer real estate secured by 1-4 family residential | First deed of trust | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	58,336	62,277
Consumer real estate secured by 1-4 family residential | First deed of trust | Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	42
Consumer real estate secured by 1-4 family residential | First deed of trust | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	42
Consumer real estate secured by 1-4 family residential | Second deed of trust
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	5,653	12,118	12,118
Total Loans	5,653	12,118
Consumer real estate secured by 1-4 family residential | Second deed of trust | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	5,647	12,118
Consumer real estate secured by 1-4 family residential | Second deed of trust | Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6
Consumer real estate secured by 1-4 family residential | Second deed of trust | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6
Commercial and industrial loans | Commercial and industrial loans (except those secured by real estate)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	85,119	100,421	100,421
Total Loans	85,119	100,421
Commercial and industrial loans | Commercial and industrial loans (except those secured by real estate) | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	84,539	99,390
Commercial and industrial loans | Commercial and industrial loans (except those secured by real estate) | Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	580	1,031
Commercial and industrial loans | Commercial and industrial loans (except those secured by real estate) | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	423	1,031
Commercial and industrial loans | Commercial and industrial loans (except those secured by real estate) | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	157
Commercial and industrial loans | Guaranteed student loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	23,413	25,975	$ 25,975
Total Loans	23,413	25,975
Recorded Investment, 90 Days and Accruing	1,638	1,961
Commercial and industrial loans | Guaranteed student loans | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	19,844	22,267
Commercial and industrial loans | Guaranteed student loans | Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,569	3,708
Commercial and industrial loans | Guaranteed student loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,141	956
Commercial and industrial loans | Guaranteed student loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	790	791
Commercial and industrial loans | Guaranteed student loans | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,638	1,961
Commercial and industrial loans | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,758	3,003
Total Loans	3,758	3,003
Commercial and industrial loans | Consumer and other | Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$ 3,758	$ 3,003