Loans Payable - Interest accrued and accumulated amortization of capitalized issuance costs (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Accrued interest	$ 142,493	$ 232,401
Accumulated amortization of capitalized issuance costs	1,347,725	1,151,501
Amortization and preferred stock dividends on mandatorily redeemable preferred stock
Debt Instrument [Line Items]
Accrued interest	70,004	70,004
Accumulated amortization of capitalized issuance costs	1,029,314	832,693
Franklin Square Property
Debt Instrument [Line Items]
Accrued interest	42,046	43,448
Accumulated amortization of capitalized issuance costs	80,387	59,108
Hanover Square Property
Debt Instrument [Line Items]
Accrued interest		55,755
Accumulated amortization of capitalized issuance costs		71,696
Ashley Plaza Property
Debt Instrument [Line Items]
Accrued interest		34,580
Accumulated amortization of capitalized issuance costs	88,612	75,539
Brookfield Center Property.
Debt Instrument [Line Items]
Accumulated amortization of capitalized issuance costs	56,756	48,244
Parkway Center
Debt Instrument [Line Items]
Accrued interest	30,443	28,614
Accumulated amortization of capitalized issuance costs	32,160	23,890
Wells Fargo Mortgage Facility
Debt Instrument [Line Items]
Accumulated amortization of capitalized issuance costs	$ 60,496	$ 40,331