CHANGE IN OPERATING WORKING CAPITAL (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013		Dec. 31, 2013 GTN Former parent, TransCanada subsidiaries Transaction between entities under common control Accounts payable to affiliates
CHANGE IN OPERATING WORKING CAPITAL
Change in accounts receivable and other	$ 7	$ 6
Change in accounts payable and accrued liabilities	4	(2)
Change in accounts payable to affiliates	17	(1)	[1]
Change in accrued interest		(1)
Change in operating working capital	28	2	[2]
Business Acquisition [Line Items]
Carty Lateral accrual				$ 25

[1] (b) Excludes Carty Lateral accrual of $25 million at December 31, 2013.

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