Property Loans, Net of Loan Loss Allowances - Summary of Partnership's Remaining Property Loan Commitments (Details)	9 Months Ended
	Sep. 30, 2021 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Maximum Remaining Commitment	$ 152,121,106
Centennial Crossings [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Sep. 01, 2023	[1]
Maximum Remaining Commitment	$ 21,232,271
Centennial Crossings [Member] | LIBOR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	2.50%	[2]
Hilltop at Signal Hills [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Aug. 01, 2023	[1]
Maximum Remaining Commitment	$ 20,197,939
Hilltop at Signal Hills [Member] | SOFR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	3.07%	[2]
Legacy Commons at Signal Hills [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Feb. 01, 2024	[1]
Maximum Remaining Commitment	$ 31,233,972
Legacy Commons at Signal Hills [Member] | SOFR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	3.07%	[2]
Oasis at Twin Lakes [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Aug. 01, 2023	[1]
Maximum Remaining Commitment	$ 13,755,209
Oasis at Twin Lakes [Member] | LIBOR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	2.50%	[2]
Scharbauer Flats Apartments [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Jan. 01, 2023	[1]
Maximum Remaining Commitment	$ 20,850,387
Scharbauer Flats Apartments [Member] | LIBOR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	2.85%
Osprey Village [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Aug. 01, 2024	[1]
Maximum Remaining Commitment	$ 24,500,000
Osprey Village [Member] | SOFR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	3.07%	[2]
Willow Place Apartments [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	Oct. 01, 2024	[1]
Maximum Remaining Commitment	$ 20,351,328
Willow Place Apartments [Member] | SOFR [Member]
Accounts Notes And Loans Receivable [Line Items]
Variable interest rate	3.30%	[3]

[1] The borrower may elect to extend the maturity date for a period ranging between six and twelve months upon meeting certain conditions, including payment of a non-refundable extension fee.

[2] The index is subject to a floor of 0.5%

[3] The index is subject to a floor of 0.25%