MORTGAGE LOAN RECEIVABLES - Provision for Loan Losses (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Allowance for Loan and Lease Losses [Roll Forward] | ||
| Provision for loan losses at beginning of period | $ 4,000 | $ 4,000 |
| Provision for loan losses | 3,000 | 0 |
| Provision for loan losses at end of period | $ 7,000 | $ 4,000 |