MEMBERS' EQUITY Table 4 (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Distribution Made to Limited Liability Company (LLC) Member [Line Items]
Cash distributions per unit applicable to members (distribution earned)	$ 0.545	$ 0.545	$ 0.545	$ 0.545	$ 1.090	$ 1.090
Total cash distributions (distribution earned)	$ 23,250	$ 23,248	$ 23,249	$ 23,236	$ 46,498	$ 46,458
Distribution date of record (distribution earned)	Aug. 06, 2014	May 07, 2014	Feb. 10, 2014
Distribution payment date (distribution earned)	Aug. 14, 2014	May 15, 2014	Feb. 18, 2014
Distribution announcement date (distribution earned)	Jul. 25, 2014