SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended	1 Months Ended
	Dec. 31, 2011 M	May 31, 2011 GTN	May 31, 2011 Bison	Jul. 31, 2009 North Baja Pipeline, LLC
Acquisitions
Interest acquired by the Partnership (as a percent)		25.00%	25.00%	100.00%
Cash and Cash Equivalents
Maximum term of original maturity to classify instruments as cash equivalents (in months)	3