ORGANIZATION (Details 2)			1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	May 31, 2011 General Partner	Sep. 30, 2011 General Partner	Sep. 30, 2011 General Partner	Dec. 31, 2010 General Partner	Sep. 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%	2.00%
Number of common units owned	53,500,000	46,200,000		5,797,106	5,797,106		11,287,725
Additional ownership interest in the Partnership (as a percent)							20.70%
Aggregate ownership interest in the Partnership (as a percent)					12.60%	14.30%	33.30%