MEMBERS' EQUITY Table 1 (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Changes to our members’ equity
Balance as of December 31, 2010			$ 541,463
Net income	22,061	30,886	32,244	39,379
Distributions to unitholders			(40,844)	(37,626)
Other comprehensive loss			(3,290)
Unit-based compensation			1,088
Balance as of June 30, 2011	$ 530,661		$ 530,661