Loans - Credit quality indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Jun. 30, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	$ 496,198	$ 479,669
Residential and Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	188,533	196,663
Residential and Consumer Loan | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	185,431	191,424
Residential and Consumer Loan | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	3,102	5,239
Commercial Loan Total
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	307,665	283,006
Commercial Loan Total | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	304,889	279,923
Commercial Loan Total | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,622	1,773
Commercial Loan Total | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,154	1,310
Residential real estate | 1-4 Family
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	142,055	147,061
Residential real estate | Home equity and HELOCs
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	32,527	32,529
Residential real estate | Construction Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	11,736	14,834
Residential real estate | Residential and Consumer Loan | 1-4 Family
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	142,055	147,061
Residential real estate | Residential and Consumer Loan | 1-4 Family | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	139,160	142,280
Residential real estate | Residential and Consumer Loan | 1-4 Family | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,895	4,781
Residential real estate | Residential and Consumer Loan | Home equity and HELOCs
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	32,527	32,529
Residential real estate | Residential and Consumer Loan | Home equity and HELOCs | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	32,436	32,188
Residential real estate | Residential and Consumer Loan | Home equity and HELOCs | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	91	341
Residential real estate | Residential and Consumer Loan | Construction Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	11,736	14,834
Residential real estate | Residential and Consumer Loan | Construction Residential | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	11,736	14,834
Commercial real estate | 1 - 4 family investor
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	99,589	96,850
Commercial real estate | 1 - 4 family investor | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	98,151	95,271
Commercial real estate | 1 - 4 family investor | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	1,344	1,473
Commercial real estate | 1 - 4 family investor | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	94	106
Commercial real estate | Multi-family (five or more)
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,595	13,069
Commercial real estate | Multi-family (five or more) | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,320	12,778
Commercial real estate | Multi-family (five or more) | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	275	291
Commercial real estate | Commercial non-residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	166,154	158,727
Commercial real estate | Commercial non-residential | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	165,091	157,514
Commercial real estate | Commercial non-residential | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	278	300
Commercial real estate | Commercial non-residential | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	785	913
Commercial real estate | Construction and Land
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	10,750	4,951
Commercial real estate | Construction and Land | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	10,750	4,951
Commercial real estate | Construction and Land | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	0
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,577	9,409
Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	15,577	9,409
Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	0
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,215	2,239
Consumer | Residential and Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,215	2,239
Consumer | Residential and Consumer Loan | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	2,099	2,122
Consumer | Residential and Consumer Loan | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans	$ 116	$ 117