LOANS RECEIVABLE AND OTHER INVESTMENTS - Composition of Loans Receivable and Other Investments (Details) $ in Thousands	Jun. 30, 2020 USD ($) preferred_equity_investment Investment loan	Dec. 31, 2019 USD ($)
Loans Receivable:
Quantity | loan	19
Principal balance	$ 67,719	$ 67,527
Book Value	63,781	63,634
Allowance for loan losses	(1,375)	(564)
Book Value	$ 62,406	63,070
Weighted Average Contractual Interest Rate / Rate of Return	7.70%
Weighted Average Annualized Effective Interest Rate / Rate of Return	7.90%
Other Investments:
Quantity | preferred_equity_investment	5
Principal Balance	$ 21,848	43,893
Book Value	$ 21,995	44,304
Weighted Average Contractual Interest Rate / Rate of Return	12.50%
Weighted Average Annualized Effective Interest Rate / Rate of Return	12.50%
Total Quantity | Investment	24
Total Principal Balance	$ 89,567
Total Book Value	$ 84,401	107,374
Total Weighted Average Contractual Interest Rate / Rate of Return	8.90%
Total Weighted Average Annualized Effective Interest Rate / Rate of Return	9.10%
Mortgage
Loans Receivable:
Quantity | loan	1
Principal balance	$ 19,000
Book Value	$ 19,000	19,000
Weighted Average Contractual Interest Rate / Rate of Return	10.00%
Weighted Average Annualized Effective Interest Rate / Rate of Return	10.00%
Construction
Loans Receivable:
Quantity | loan	1
Principal balance	$ 3,276
Book Value	$ 3,294	2,487
Weighted Average Contractual Interest Rate / Rate of Return	8.00%
Weighted Average Annualized Effective Interest Rate / Rate of Return	7.80%
Other
Loans Receivable:
Quantity | loan	17
Principal balance	$ 45,443
Book Value	$ 41,487	$ 42,147
Weighted Average Contractual Interest Rate / Rate of Return	6.80%
Weighted Average Annualized Effective Interest Rate / Rate of Return	6.90%