SUBSEQUENT EVENTS (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended				9 Months Ended	0 Months Ended												0 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Northern Border	Sep. 30, 2014 Great Lakes	Mar. 31, 2014 Great Lakes	Sep. 30, 2014 GTN	Jul. 02, 2013 Bison Former parent, TransCanada subsidiaries Transaction between entities under common control	Oct. 23, 2014 Subsequent event	Nov. 03, 2014 Subsequent event GTN Expected	Oct. 14, 2014 Subsequent event GTN	Oct. 14, 2014 Subsequent event Bison	Oct. 01, 2014 Subsequent event Bison	Oct. 21, 2014 Subsequent event Distribution declared Northern Border	Oct. 14, 2014 Subsequent event Distribution declared Great Lakes	Nov. 03, 2014 Subsequent event Cash Distribution Paid Northern Border Expected	Nov. 03, 2014 Subsequent event Cash Distribution Paid Great Lakes Expected	Oct. 01, 2014 Subsequent event Short-Term Loan Facility	Oct. 01, 2014 Subsequent event Short-Term Loan Facility LIBOR	Oct. 01, 2014 Subsequent event Bison Former parent, TransCanada subsidiaries Transaction between entities under common control	Oct. 01, 2014 Subsequent event Bison Former parent, TransCanada subsidiaries Transaction between entities under common control
Acquisition
Business Acquisition, Percentage of Voting Interests Acquired						45.00%													30.00%
Purchase price																		$ 215
Short-term financing
Amount borrowed																	170
Term of borrowing																364 days
Distributions
Cash distribution (in dollars per unit)							$ 0.84
Distribution declared									26	16
Ownership interest (as a percent)					70.00%	70.00%					100.00%
Distribution received by Partnership								18
Partnership distribution	199											38	8
Ownership interest (as a percent)		50.00%	46.45%	46.45%
Partnership's share of distributions														$ 19	$ 4