Loans - Credit quality indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	$ 480,856	$ 478,920
Residential and Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	178,843	196,750
Residential and Consumer Loan | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	176,671	191,511
Residential and Consumer Loan | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,172	5,239
Commercial Loan Total
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	302,013	282,170
Commercial Loan Total | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	298,921	279,087
Commercial Loan Total | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,231	1,773
Commercial Loan Total | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,861	1,310
Residential real estate | 1-4 Family
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	135,046	147,143
Residential real estate | Home equity and HELOCs
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	32,684	32,590
Residential real estate | Construction Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	9,113	14,778
Residential real estate | Residential and Consumer Loan | 1-4 Family
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	135,046	147,143
Residential real estate | Residential and Consumer Loan | 1-4 Family | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	132,956	142,362
Residential real estate | Residential and Consumer Loan | 1-4 Family | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,090	4,781
Residential real estate | Residential and Consumer Loan | Home equity and HELOCs
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	32,684	32,590
Residential real estate | Residential and Consumer Loan | Home equity and HELOCs | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	32,684	32,249
Residential real estate | Residential and Consumer Loan | Home equity and HELOCs | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans		341
Residential real estate | Residential and Consumer Loan | Construction Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	9,113	14,778
Residential real estate | Residential and Consumer Loan | Construction Residential | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	9,113	14,778
Commercial real estate | 1 - 4 family investor
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	98,160	96,508
Commercial real estate | 1 - 4 family investor | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	96,097	94,929
Commercial real estate | 1 - 4 family investor | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,231	1,473
Commercial real estate | 1 - 4 family investor | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	832	106
Commercial real estate | Multi-family (five or more)
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,281	13,015
Commercial real estate | Multi-family (five or more) | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,030	12,724
Commercial real estate | Multi-family (five or more) | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	251	291
Commercial real estate | Commercial non-residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	157,555	158,294
Commercial real estate | Commercial non-residential | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	156,777	157,081
Commercial real estate | Commercial non-residential | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans		300
Commercial real estate | Commercial non-residential | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	778	913
Commercial real estate | Construction and Land
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,584	4,942
Commercial real estate | Construction and Land | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,584	4,942
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,433	9,411
Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,433	9,411
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,000	2,239
Consumer | Residential and Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,000	2,239
Consumer | Residential and Consumer Loan | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,918	2,122
Consumer | Residential and Consumer Loan | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	$ 82	$ 117