CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY (Parenthetical) $ in Millions	9 Months Ended
Sep. 30, 2016 USD ($)
Losses expected to be reclassified to Net Income in the next 12 months	$ 1
Transaction between entities under common control \| Former parent, TransCanada subsidiaries \| Portland Natural Gas Transmission System
Business Acquisition, Percentage of Voting Interests Acquired	49.90%

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

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