ORGANIZATION (Details 2)			3 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 General Partner	Jun. 30, 2011 General Partner	Dec. 31, 2010 General Partner	Jun. 30, 2011 TransCanada Corporation
Common units and interest in the partnership
General partner ownership interest in the partnership (as a percent)			2.00%	2.00%
Number of common units owned (in units)	53,500,000	46,200,000	5,797,106	5,797,106		11,287,725
Aggregate ownership interest in the Partnership (as a percent)				12.60%	14.30%	20.70%