EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Unvested service-based restricted shares (in shares)	700,000.0		700,000		700,000	700,000
Numerator:
Net income	$ 14,460	$ 11,502	$ 17,011	$ 15,508	$ 25,962	$ 32,520
Less: Income allocated to participating securities	(160)		(187)		(286)	(355)
Net income available to common stockholders	$ 14,300		$ 16,824		$ 25,676	$ 32,165
Denominator:
Weighted average shares - basic (in shares)	66,940,000		66,541,000		66,806,000	66,432,000
Performance-based restricted stock awards (in shares)	0		20,000		0	15,000
Weighted average shares - diluted (in shares)	66,940,000		66,561,000		66,806,000	66,447,000
Basic net income per share (in usd per share)	$ 0.21		$ 0.25		$ 0.38	$ 0.48
Diluted net income per share (in usd per share)	$ 0.21		$ 0.25		$ 0.38	$ 0.48