Line of Credit - Additional Information (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Line Of Credit Facility [Line Items]
Pledged Loans Aggregate Principal Amount	$ 19,145,000			$ 19,145,000
Amortization of debt issuance costs				28,000	$ 40,000
Debt issuance costs				57,000	(0)
Interest expense	$ 156,000		$ 128,000	$ 382,000	346,000
Ameribor [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, interest rate description				the Ameribor Rate plus three and one-quarter percent (3.25%); and (ii) five percent (5.0%). The fair value of the balance on the line of credit is deemed to approximate the recorded amount because the reference rate plus 3.25% and the other terms and conditions, including the two-year term, of the Revolving Line of Credit and Term Loan Agreement are reflective of market rate terms (Level 2 inputs).
Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, maximum amount outstanding during period				$ 10,000,000
Line of credit facility, conversion of outstanding principal balance to term loan of fee				0.25%
Maturity date extended				Mar. 31, 2026
Line of credit facility, description				RMI VIII has the option at the maturity date to convert - for a fee of one-quarter of one percent (0.25%) – the then outstanding principal balance to a two-year term loan maturing in March 2026.
Line of credit facility, interest rate description				per annum rate of the greater of (i) five percent (5%) or (ii) the sum of the one-month LIBOR rate plus three and one-quarter percent (3.25%).
Line of credit facility, interest rate	5.00%			5.00%
Interest rate, increase (decrease)				0.25%
Line of credit facility, unused line of fee				0.50%
Line of Credit Facility, Commitment Fee Description				there is a quarterly unused line fee equal to one-half of one percent (0.50%) per annum of the average daily difference between the average principal outstanding and fifty percent (50%) of the maximum principal of $10 million ($5,000,000).
Pledged Loans Aggregate Principal Amount						$ 21,487,000
Pledged loans, advance amount	$ 10,000,000			$ 10,000,000
Amortization of debt issuance costs	$ 7,000		$ 13,000	28,000	$ 40,000
Debt issuance costs				$ 57,000
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, interest rate	3.25%			3.25%
Revolving Credit Facility [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Minimum compensating balance amount	$ 1,000,000.0			$ 1,000,000.0
Revolving Credit Facility [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, average rate				50.00%
Line Of Credit [Member]
Line Of Credit Facility [Line Items]
Interest rate, increase (decrease)		5.65%
Minimum tangible net worth	$ 50,000,000			$ 50,000,000
Debt instrument, covenant description				the partnership shall maintain (i) minimum tangible net worth of $50 million, net of amounts due from related companies; (ii) debt service coverage ratio at all times of not less than 2.00 to 1.00;
Line Of Credit [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt service coverage ratio				1.00
Line Of Credit [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Debt service coverage ratio				2.00
Line Of Credit [Member] | Maximum [Member] | Financial Asset, 61 Days Past Due [Member]
Line Of Credit Facility [Line Items]
Delinquency rate				10.00%