EARNINGS PER UNIT (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net loss attributable to limited partners	$ (36,926)	$ (5,988)
Phantom Units
Loss per limited partner unit:
Nonvested anti-dilutive phantom units excluded from the calculation of diluted EPU (in shares)	34	4
Series A Preferred Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net loss attributable to limited partners	$ 7,125	$ 7,125
Common units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net loss attributable to limited partners	$ (44,051)	$ (13,113)
Weighted-average common units outstanding – basic and diluted	75,793	73,134
Loss per limited partner unit:
Basic (in dollars per share)	$ (0.58)	$ (0.18)
Diluted (in dollars per share)	$ (0.58)	$ (0.18)