Loans - Risk category of loans (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
Commercial real estate [Member] | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	85,612,836	80,603,153	63,032,800
Commercial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	100,856,113	99,964,364
Commercial [Member] | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	85,612,836	80,603,153
Commercial [Member] | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	7,830,296	8,778,723	8,901,181
Commercial [Member] | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	7,412,981	10,582,488	$ 8,098,343
Commercial [Member] | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	99,384,734	98,575,589
Commercial [Member] | Pass | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	84,141,457	79,214,378
Commercial [Member] | Pass | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	7,830,296	8,778,723
Commercial [Member] | Pass | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	7,412,981	10,582,488
Commercial [Member] | Special Mention/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	1,471,379	1,388,775
Commercial [Member] | Special Mention/Watch | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 1,471,379	$ 1,388,775