LOANS HELD-FOR-INVESTMENT (Schedule of Loans Held for Investment) (Details) - USD ($)	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-investment and related receivables, net	$ 626,079,000		$ 301,630,000
Less: Allowance for credit losses	(27,684,000)	$ (19,779,000)	0
Total loans held-for-investment and related receivables, net	598,395,000		301,630,000
Mezzanine loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-investment and related receivables, net	140,086,000		146,060,000
Less: Allowance for credit losses	(21,269,000)	(14,541,000)	0
Total loans held-for-investment and related receivables, net	118,800,000
Senior loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-investment and related receivables, net	113,682,000		152,820,000
Less: Allowance for credit losses	(492,000)	(809,000)	0
Total CRE loans-held-for-investment and related receivables, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-investment and related receivables, net	253,768,000		298,880,000
Total loans held-for-investment and related receivables, net	232,007,000		298,880,000
Broadly syndicated loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-investment and related receivables, net	372,311,000		2,750,000
Less: Allowance for credit losses	(5,923,000)	$ (4,429,000)	0
Total loans held-for-investment and related receivables, net	$ 366,388,000		$ 2,750,000