Loans - Secured Loans Summarized by Payment Delinquency (Details) $ in Thousands	Sep. 30, 2023 USD ($) Loan	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($) Loan
Loans (Details) - Secured Loans by Property Type [Line Items]
Delinquent loans, number \| Loan	14		21
Principal \| $	$ 54,589	$ 57,292	$ 60,088
Current [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Delinquent loans, number \| Loan	10		18
Principal \| $	$ 34,474		$ 54,359
Past Due 30-89 Days [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Delinquent loans, number \| Loan	0		0
Principal \| $	$ 0		$ 0
Past Due 90-179 Days [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Delinquent loans, number \| Loan	0		2
Principal \| $	$ 0		$ 2,009
Past Due 180 Days or More [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Delinquent loans, number \| Loan	4		1
Principal \| $	$ 20,115		$ 3,720
Past Due [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Delinquent loans, number \| Loan	4		3
Principal \| $	$ 20,115		$ 5,729

REDWOOD MORTGAGE INVESTORS VIII 10-Q