IMPAIRMENT OF EQUITY INVESTMENTS (Details) - CAD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Impairment loss on equity method investments	$ 1,736	$ 0
Loss from equity investments	(163)	$ (413)
DCP Midstream, LLC
Schedule of Equity Method Investments [Line Items]
Loss from equity investments	324
Carrying value of investment	$ 341		$ 2,193

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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