CHANGES IN OPERATING WORKING CAPITAL (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CHANGES IN OPERATING WORKING CAPITAL
Decrease/(increase) in Accounts receivable	$ 31	$ (69)	$ (576)
Increase in Inventories	(42)	(49)	(38)
Decrease in Assets held for sale	0	0	14
(Increase)/decrease in Other current assets	(15)	45	189
Increase/(decrease) in Accounts payable and other	352	(70)	151
(Decrease)/increase in Accrued interest	(33)	41	12
Decrease in Liabilities related to Assets held for sale	0	0	(25)
Decrease/(increase) in Operating Working Capital	$ 293	$ (102)	$ (273)

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- Definition

Increase (Decrease ) In Liabilities Related To Assets Held For Sale

+ References

No definition available.

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- Definition

Amount of increase (decrease) in obligations incurred but not paid, and operating obligations classified as other.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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- Definition

The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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- Definition

The increase (decrease) during the period in book value of long-lived assets that the reporting entity plans to sell within one year (or one business cycle).

+ References

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- Definition

The increase (decrease) during the reporting period in interest payable, which represents the amount owed to note holders, bond holders, and other parties for interest earned on loans or credit extended to the reporting entity.

+ References

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- Definition

The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.

+ References

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- Definition

The increase (decrease) during the reporting period of all assets and liabilities used in operating activities.

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- Definition

Amount of increase (decrease) in current assets classified as other.

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