EARNINGS PER COMMON UNIT (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income (loss) attributable to the period	$ 16,832	$ (764)	$ 18,474	$ (164,685)
Less: net income (loss) allocated to participating securities	(62)	(2)	(141)	(26)
Net income (loss) attributable to common unitholders	$ 16,770	$ (766)	$ 18,333	$ (164,711)
Basic weighted average common units outstanding (in shares)	64,152,000	67,847,000	64,724,000	67,832,000
Effect of dilutive securities:
Effect of dilutive securities: Potential common units issuable (in shares)	89,000	0	91,000	0
Diluted weighted average common units outstanding (in shares)	64,241,000	67,847,000	64,815,000	67,832,000
Net income (loss) per common unit, basic (in USD per share)	$ 0.26	$ (0.01)	$ 0.29	$ (2.43)
Net income (loss) per common unit, diluted (in USD per share)	$ 0.26	$ (0.01)	$ 0.29	$ (2.43)
Anti-dilutive for potentially dilute basic earnings per common unit (in shares)			2,955	0