Loans - Secured Loan Principal Transactions (Parenthetical) (Details) - USD ($) $ in Thousands	Jan. 31, 2022	Dec. 31, 2021
Receivables [Abstract]
Recorded investment	$ 464,000	$ 300

Amount Includes Principal Collected and Held in Trust.

No definition available.

Name:	ck0000889123_AmountIncludesPrincipalCollectedAndHeldInTrust
Namespace Prefix:	ck0000889123_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant