INTANGIBLE AND OTHER ASSETS - Schedule of PPA intangible and other assets (Details) - CAD CAD in Millions	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Cost	CAD 0	CAD 810
Accumulated Amortization	0	590
Net Book Value	0	220
Sheerness (expires 2020)
Finite-Lived Intangible Assets [Line Items]
Cost	0	585
Accumulated Amortization	0	390
Net Book Value	0	195
Sundance A (expires 2017)
Finite-Lived Intangible Assets [Line Items]
Cost	0	225
Accumulated Amortization	0	200
Net Book Value	CAD 0	CAD 25

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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