Loans - Secured Loan Principal Transactions (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Principal, beginning of period		$ 86,203	$ 97,438
Loans funded		7,718	63,600
Principal collected		(10,798)	(67,095)
Loan transferred to related mortgage fund		(3,374)
Loans sold to non-affiliate		(2,730)	(7,740)
Foreclosures	[1]	(2,939)
Principal, ending of period		$ 74,080	$ 86,203

[1] The partnership foreclosed on one loan, with a recorded investment of approximately $3,163,000. The net investment in the loan was adjusted to the estimated fair value of the related collateral, net of any costs to sell in arriving at net realizable value and net of any senior loans, which resulted in the recognition of foregone interest of approximately $140,000.