MEMBERS' EQUITY Table 1 (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes in Members' Equity [Roll Forward]
Balance as of January 1, 2016			$ 287,070
Net income	$ 15,073	$ 15,527	31,749	$ 42,332
Distributions to unitholders			(46,794)	$ (46,791)
Other comprehensive income (loss)			(10,184)
Unit-based compensation expense			309
Balance as of June 30, 2016	$ 262,150		$ 262,150