MEMBERS' EQUITY Table 4 (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended					9 Months Ended		0 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Oct. 31, 2014 Subsequent Event [Member]
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	$ 0.545	$ 1.635	$ 1.635
Total cash distributions (distribution earned)	$ 23,351	$ 23,250	$ 23,248	$ 23,249	$ 23,231	$ 69,849	$ 69,689
Distribution date of record (distribution earned)	Nov. 10, 2014	Aug. 06, 2014	May 07, 2014	Feb. 10, 2014
Distribution payment date (distribution earned)	Nov. 19, 2014	Aug. 14, 2014	May 15, 2014	Feb. 18, 2014
Distribution announcement date (distribution earned)								Oct. 31, 2014