Loans - loans by class based on payment activity (Details) - USD ($)	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 194,757,902	$ 187,900,474	$ 158,582,539
Residential [Member] | One-to-four-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	56,704,945	51,890,948	51,680,119
Residential [Member] | One-to-four-family residential | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	56,649,642	51,827,163
Residential [Member] | One-to-four-family residential | Non-performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	55,303	63,785
Residential [Member] | Multi-family real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	35,113,319	33,944,903	24,615,280
Residential [Member] | Multi-family real estate | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	35,113,319	33,944,903
Residential Real Estate And Consumer Portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	93,901,789	87,936,110
Residential Real Estate And Consumer Portfolio | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	93,846,486	87,872,325
Residential Real Estate And Consumer Portfolio | Non-performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	55,303	63,785
Consumer Loans [Member] | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	2,083,525	2,100,259	$ 2,254,816
Consumer Loans [Member] | Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 2,083,525	$ 2,100,259