EQUITY-BASED COMPENSATION - Time-Based Restricted Stock Awards (Details) - Restricted Stock Awards - Time-Based - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Non-vested at the beginning of year (in shares)	391,477	357,845
Granted (in shares)	185,930	156,318
Vested (in shares)	(205,619)	(120,366)
Forfeited (in shares)	(1,636)	(2,320)
Non-vested at end of year (in shares)	370,152	391,477	357,845
Weighted Average Grant Date Fair Value per Share
Non-vested at beginning of year (in dollars per share)	$ 13.52	$ 11.90
Granted (in dollars per share)	13.15	15.52
Vested (in dollars per share)	13.41	11.29
Forfeited (in dollars per share)	12.84	13.70
Non-vested at end of year (in dollars per share)	$ 13.40	$ 13.52	$ 11.90
Aggregate Current Value
Non-vested outstanding	$ 3,602
Total fair value of awards vested	$ 2,800	$ 1,400	$ 900
Employees
Equity-based compensation
Vesting period	4 years
Employees | Period one
Equity-based compensation
Vesting percentage	20.00%
Employees | Period two
Equity-based compensation
Vesting percentage	20.00%
Employees | Period three
Equity-based compensation
Vesting percentage	20.00%
Employees | Period four
Equity-based compensation
Vesting percentage	40.00%
Executive officers
Equity-based compensation
Vesting period	3 years
Executive officers | Period one
Equity-based compensation
Vesting percentage	25.00%
Executive officers | Period two
Equity-based compensation
Vesting percentage	25.00%
Executive officers | Period three
Equity-based compensation
Vesting percentage	50.00%