EARNINGS PER COMMON UNIT (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income (loss) attributable to the period	$ 4,662	$ (21,752)	$ 1,642	$ (163,921)
Less: net income (loss) allocated to participating securities	(55)	(4)	(79)	(24)
Net income (loss) attributable to common unitholders	4,607	(21,756)	1,563	(163,945)
Net income (loss) attributable to common unitholders	$ 4,607	$ (21,756)	$ 1,563	$ (163,945)
Basic weighted average common units outstanding (in shares)	64,672,000	67,831,000	65,014,000	67,827,000
Effect of dilutive securities:
Effect of dilutive securities: Potential common units issuable (in shares)	123,000	0	137,000	0
Diluted weighted average common units outstanding (in shares)	64,795,000	67,831,000	65,151,000	67,827,000
Net income (loss) per common unit, basic (in USD per share)	$ 0.07	$ (0.32)	$ 0.03	$ (2.42)
Net income (loss) per common unit, diluted (in USD per share)	$ 0.07	$ (0.32)	$ 0.03	$ (2.42)
Anti-dilutive for potentially dilute basic earnings per common unit (in shares)	39	0	4,974	0