RELATED PARTY TRANSACTIONS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Blackstone and First Reserve [Member] | Series B Units [Member]
Related Party Transaction [Line Items]
Distributions to Series B Unitholders	$ 130,523	$ 6,427	$ 0
Fuel Strategies International, Inc, [Member]
Related Party Transaction [Line Items]
Charges incurred during period	588	646		903
Executive Chairman of the Board of Directors [Member]
Related Party Transaction [Line Items]
Charges incurred during period	$ 1,214	$ 1,274		$ 1,030