EARNINGS PER UNIT (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net (loss) income attributable to limited partners	$ (51,111)	$ 8,806	$ (57,099)	$ 6,029
Phantom Units
(Loss) earnings per limited partner unit:
Nonvested anti-dilutive phantom units excluded from the calculation of diluted EPU (in shares)	1	0	3	0
Series A Preferred Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net (loss) income attributable to limited partners	$ 7,125	$ 0	$ 14,250	$ 0
Common units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net (loss) income attributable to limited partners	$ (58,236)	$ 8,806	$ (71,349)	$ 6,029
Weighted-average units outstanding (in shares)	73,356	72,532	73,245	72,341
Effect of nonvested phantom units (in shares)	0	310	0	367
Weighted-average units outstanding – diluted (shares)	73,356	72,842	73,245	72,708
(Loss) earnings per limited partner unit:
Basic (in dollars per share)	$ (0.79)	$ 0.12	$ (0.97)	$ 0.08
Diluted (in dollars per share)	$ (0.79)	$ 0.12	$ (0.97)	$ 0.08

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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