Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

+ Details

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- Definition

Percentage of voting equity interests acquired in a business combination achieved in stages, including equity interests in the acquiree held by the acquirer immediately before the acquisition date and acquired at the acquisition date.

+ References

No definition available.

+ Details

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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- Details

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- Details

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SIGNIFICANT ACCOUNTING POLICIES - Ownership Interests Acquired (Details)	Apr. 01, 2015	Mar. 31, 2015	Oct. 01, 2014	Sep. 30, 2014	Jul. 01, 2013
TransCanada \| GTN
Acquisitions
Remaining noncontrolling ownership interest (as a percent)		30.00%
TransCanada \| Bison
Acquisitions
Remaining noncontrolling ownership interest (as a percent)				30.00%
GTN \| Former parent, TransCanada subsidiaries \| Transaction between entities under common control
Acquisitions
Interest acquired (as a percent)	30.00%				45.00%
Ownership interest, including acquired interest (as a percent)					70.00%
Bison \| Former parent, TransCanada subsidiaries \| Transaction between entities under common control
Acquisitions
Interest acquired (as a percent)			30.00%		45.00%
Ownership interest, including acquired interest (as a percent)					70.00%