SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Issued Accounting Update (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect of ASU 2017-12 adoption	$ 0
Accumulated Other Comprehensive Income (Loss)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect of ASU 2017-12 adoption	795
Accumulated Other Comprehensive Income (Loss) | Accounting Standards Update 2017-12
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect of ASU 2017-12 adoption	800
Cumulative Distributions in Excess of Net Income
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect of ASU 2017-12 adoption	(795)
Cumulative Distributions in Excess of Net Income | Accounting Standards Update 2017-12
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect of ASU 2017-12 adoption	$ (800)