EARNINGS PER COMMON UNIT (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic earnings per unit:
Net income (loss)		$ (9,411)	$ 89,079	$ 22,046
Basic earnings per unit:
Weighted Average Common Units (in units)		23,973,850	23,527,469	23,219,680
Weighted average phantom units deemed participating securities (in units)		0	542,949	795,882
Total (in units)	[1]	23,973,850	24,070,418	24,015,562
Earning (loss) per common unit (basic) (in dollars per unit)	[1]	$ (0.39)	$ 3.70	$ 0.92
Diluted earnings per unit:
Weighted Average Common Units (in units)		23,973,850	23,527,469	23,219,680
Weighted average phantom units deemed participating securities (in units)		0	542,949	795,882
Weighted average potentially dilutive units outstanding (in units)		0	6,019	6,395
Total (in units)	[1]	23,973,850	24,076,437	24,021,957
Earnings (loss) per common unit (diluted) (in dollars per unit)	[1]	$ (0.39)	$ 3.70	$ 0.92
Phantom Units
Earnings Per Share [Line Items]
Antidilutive securities excluded form computation of EPS		170,720

[1] See Note 15.