MORTGAGE LOANS, NET - Loans by State (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Loan Loans	Dec. 31, 2017 USD ($) Loan Loans	Dec. 31, 2016 USD ($)
Mortgage Loans on Real Estate [Line Items]
Outstanding Principal and Interest	$ 36,297	$ 32,350
Less: valuation allowance	(13,063)	(12,682)	$ (12,682)
Net carrying value	$ 23,234	$ 19,668	$ 378
Loan Percentage	100.00%	100.00%
Number of loans | Loan	6	4
California [Member]
Mortgage Loans on Real Estate [Line Items]
Outstanding Principal and Interest	$ 12,682	$ 12,682
Less: valuation allowance	(12,682)	(12,682)
Net carrying value	$ 0	$ 0
Loan Percentage	34.90%	39.20%
Number of loans | Loan	2	2
Missouri [Member]
Mortgage Loans on Real Estate [Line Items]
Outstanding Principal and Interest	$ 8,317	$ 7,329
Less: valuation allowance	(381)	0
Net carrying value	$ 7,936	$ 7,329
Loan Percentage	22.90%	22.70%
Number of loans | Loan	1	1
Texas [Member]
Mortgage Loans on Real Estate [Line Items]
Outstanding Principal and Interest	$ 12,298	$ 12,339
Less: valuation allowance	0	0
Net carrying value	$ 12,298	$ 12,339
Loan Percentage	33.90%	38.10%
Number of loans | Loans	1	1
New York [Member]
Mortgage Loans on Real Estate [Line Items]
Outstanding Principal and Interest	$ 3,000	$ 0
Less: valuation allowance	0	0
Net carrying value	$ 3,000	$ 0
Loan Percentage	8.30%	0.00%
Number of loans | Loans	1	0
Arizona [Member]
Mortgage Loans on Real Estate [Line Items]
Outstanding Principal and Interest	$ 0	$ 0
Less: valuation allowance	0	0
Net carrying value	$ 0	$ 0
Loan Percentage	0.00%	0.00%
Number of loans | Loan	1	0