RELATED PARTY TRANSACTIONS (Details) (USD $) In Millions, unless otherwise specified				3 Months Ended				12 Months Ended																															3 Months Ended	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2012 GTN and Bison	Jun. 30, 2013 Bison	Dec. 31, 2013 Northern Border	Dec. 31, 2013 Great Lakes	Mar. 31, 2013 Great Lakes	Dec. 31, 2013 General Partner	Dec. 31, 2012 General Partner	Dec. 31, 2011 General Partner	Dec. 31, 2013 TransCanada's subsidiaries GTN	Dec. 31, 2012 TransCanada's subsidiaries GTN	Dec. 31, 2011 TransCanada's subsidiaries GTN	Dec. 31, 2013 TransCanada's subsidiaries Bison	Dec. 31, 2012 TransCanada's subsidiaries Bison	Dec. 31, 2011 TransCanada's subsidiaries Bison	Dec. 31, 2013 TransCanada's subsidiaries North Baja	Dec. 31, 2012 TransCanada's subsidiaries North Baja	Dec. 31, 2011 TransCanada's subsidiaries North Baja	Dec. 31, 2013 TransCanada's subsidiaries Tuscarora	Dec. 31, 2012 TransCanada's subsidiaries Tuscarora	Dec. 31, 2011 TransCanada's subsidiaries Tuscarora	Dec. 31, 2013 TransCanada's subsidiaries Northern Border	Dec. 31, 2012 TransCanada's subsidiaries Northern Border	Dec. 31, 2011 TransCanada's subsidiaries Northern Border	Dec. 31, 2013 TransCanada's subsidiaries Great Lakes	Dec. 31, 2012 TransCanada's subsidiaries Great Lakes	Dec. 31, 2011 TransCanada's subsidiaries Great Lakes	Dec. 31, 2013 TransCanada's subsidiaries Great Lakes Transportation revenues	Dec. 31, 2012 TransCanada's subsidiaries Great Lakes Transportation revenues	Dec. 31, 2011 TransCanada's subsidiaries Great Lakes Transportation revenues	Dec. 31, 2013 TransCanada's subsidiaries Great Lakes Affiliated rental revenue	Dec. 31, 2012 TransCanada's subsidiaries Great Lakes Affiliated rental revenue	Dec. 31, 2011 TransCanada's subsidiaries Great Lakes Affiliated rental revenue	Dec. 31, 2013 Former parent, TransCanada subsidiaries GTN and Bison Transaction between entities under common control		Dec. 31, 2011 Former parent, TransCanada subsidiaries GTN and Bison Transaction between entities under common control		Jun. 30, 2013 Former parent, TransCanada subsidiaries Bison	Dec. 31, 2011 Former parent, TransCanada subsidiaries Bison	Dec. 31, 2013 GTN Former parent, TransCanada subsidiaries Transaction between entities under common control Accounts payable to affiliates
Capital and operating costs charged to the pipeline systems and amount payable
Capital and operating costs charged by TransCanada's subsidiaries								$ 3	$ 3	$ 2	$ 28	$ 29	$ 33	$ 5	$ 6	$ 11	$ 4	$ 4	$ 4	$ 4	$ 4	$ 5	$ 30	$ 31	$ 29	$ 31	$ 33	$ 31
Impact on the Partnership's net income attributable to controlling interests											19	19	22	4	4	4	4	4	4	4	4	5	14	14	13	14	15	14
Amounts payable to TransCanada's subsidiaries											3	3			1		1	1			1		3	4		3	4
Percentage of capital and operating costs charged by TransCanada's subsidiaries											100.00%			100.00%									100.00%			100.00%
Revenues from TransCanada and its affiliates																													68	77	81	1	1	1
Percentage of revenues from TransCanada and its affiliates to total revenues																													55.00%	42.00%	32.00%
Revenue from TransCanada and its affiliates included in the Partnership's equity earnings																										32	36	38
Amount included in receivables in regards to the transportation contracts with TransCanada and its affiliates																										11	10
Accrued additional consideration																																									25
Capital contribution																																			10	[1]	213	[1]	18	305
Ownership interest (as a percent)																																							75.00%
Total cash call issued to fund debt repayment				24	62	10	9
Demand loan receivable from affiliate	21	[1]	21
Demand loan payable to affiliate	$ 15	[1]	$ 15

[1] (a) Recast as discussed in Note 2 and Note 6.