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Financial Instruments Fair value of financial assets and liabilities measured at other than fair value (Details) - CAD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018
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Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | $ 3,212 | $ 3,267
Long-term debt |  |
Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | 3,070 | 3,204
Exchangeable securities |  |
Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | 326 |
Recurring fair value measurement | Long-term debt | Financial liabilities at fair value through profit or loss, category [member] |  |
Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | 3,157 | 3,181
Recurring fair value measurement | Exchangeable securities | Financial liabilities at fair value through profit or loss, category [member] |  |
Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | 342 |
Recurring fair value measurement | Level II | Long-term debt | Financial liabilities at fair value through profit or loss, category [member] |  |
Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | 3,157 | $ 3,181
Recurring fair value measurement | Level II | Exchangeable securities | Financial liabilities at fair value through profit or loss, category [member] |  |
Disclosure of fair value measurement of liabilities [line items] |  |
Financial liabilities | $ 342 |

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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity’s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity’s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Financial instruments, class [member]; Financial assets; Derivatives [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 25 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_25&doctype=Standard -URIDate 2018-03-16 + Details
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