MEMBERS' EQUITY Table 1 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in Members' Equity [Roll Forward]
Balance as of December 31, 2012			$ 412,822
Net income (loss)	12,035	19,165	35,669	(2,997)
Distributions to unitholders			(69,681)	(65,141)
Other comprehensive income (loss)			2,752
Unit-based compensation			449
Balance as of September 30, 2013	$ 382,011		$ 382,011