EQUITY-BASED COMPENSATION - Stock Options Granted under Equity Plan (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Options
Outstanding at the beginning of year (in shares)	235,000	470,000
Exercised (in shares)	0	(235,000)
Outstanding at end of year (in shares)	235,000	235,000	470,000
Exercisable at end of year (in shares)	235,000
Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 9.75	$ 9.75
Exercised (in dollars per share)	0.00	9.75
Outstanding at end of year (in dollars per share)	9.75	$ 9.75	$ 9.75
Exercisable at end of year (in dollars per share)	$ 9.75
Weighted Average Remaining Contractual Terms
Outstanding	3 years 2 months
Exercisable	3 years 2 months
Aggregate Intrinsic Value (Current Value Less Exercise Price)
Outstanding	$ 1,288	$ 1,500	$ 1,000
Exercisable	$ 1,288		800
Stock options
Total fair value of options vested		300	900
Intrinsic value of options exercised		$ 1,000	$ 1,300