RELATED PATY TRANSACTIONS - Related Party Costs Incurred (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Payable	$ 2,761	$ 3,163
Continuing Operations | Affiliated Entity
Related Party Transaction [Line Items]
Incurred	10,581	11,212	$ 10,772
Payable	2,761	3,163
Continuing Operations | Affiliated Entity | Management fees
Related Party Transaction [Line Items]
Incurred	6,311	6,268	6,188
Payable	1,581	1,576
Continuing Operations | Affiliated Entity | Incentive Fees
Related Party Transaction [Line Items]
Incurred	1,052	1,150	381
Payable	378	540
Continuing Operations | Affiliated Entity | General and administrative expenses
Related Party Transaction [Line Items]
Incurred	3,026	3,570	3,899
Payable	789	996
Continuing Operations | Affiliated Entity | Direct costs
Related Party Transaction [Line Items]
Incurred	192	224	$ 304
Payable	$ 13	$ 51