OTHER LONG-TERM LIABILITIES (Details) - CAD CAD in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Noncurrent [Abstract]
Employee post-retirement benefits (Note 22)	CAD 389	CAD 448
Fair value of derivative contracts (Note 23)	72	330
Asset retirement obligations	98	108
Guarantees (Note 26)	16	82
Other	152	215
Other Long-Term Liabilities	CAD 727	CAD 1,183

Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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This item represents a non-contingent liability for the fair value of an obligation to stand ready to perform over the term of a guaranty issued in the event that specified triggering events or conditions occur.

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Aggregated carrying amounts of obligations as of the balance sheet date, excluding long-term debt, incurred as part of the normal operations that are expected to be paid after one year or beyond the normal operating cycle, if longer. Alternate captions include Total Deferred Credits and Other Liabilities.

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Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

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Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.

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