Loans Payable - Interest accrued and accumulated amortization of capitalized issuance costs (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Accrued interest	$ 402,530	$ 214,042
Accumulated amortization of capitalized issuance costs	1,062,835	801,565
Wells Fargo Line of Credit
Debt Instrument [Line Items]
Accrued interest	6,503
Amortization and preferred stock dividends on mandatorily redeemable preferred stock
Debt Instrument [Line Items]
Accrued interest	170,004	70,004
Accumulated amortization of capitalized issuance costs	769,942	589,639
Franklin Square Property
Debt Instrument [Line Items]
Accrued interest	42,046	43,448
Accumulated amortization of capitalized issuance costs	52,015	30,736
Hanover Square Property
Debt Instrument [Line Items]
Accrued interest	57,871	38,792
Accumulated amortization of capitalized issuance costs	69,548	59,880
Ashley Plaza Property
Debt Instrument [Line Items]
Accrued interest	33,641	35,296
Accumulated amortization of capitalized issuance costs	71,181	58,109
Brookfield Center Property.
Debt Instrument [Line Items]
Accumulated amortization of capitalized issuance costs	45,406	36,893
Parkway Center
Debt Instrument [Line Items]
Accrued interest	24,655	26,502
Accumulated amortization of capitalized issuance costs	21,134	12,864
Wells Fargo Facility
Debt Instrument [Line Items]
Accrued interest	67,810
Accumulated amortization of capitalized issuance costs	$ 33,609	$ 13,444