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Income Taxes - Aggregate Current and Deferred Income Tax Charged to Equity (Details) - CAD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Income Taxes [Abstract] |  |  |
Net impact related to cash flow hedges | $ 6 | $ (12) | $ (108)
Net impact related to net investment hedges | 0 | 0 | (7)
Net actuarial gains (losses) | (7) | 5 | (4)
Income tax expense reported in equity | $ (1) | $ (7) | $ (119)

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- Definition The aggregate current and deferred tax relating to particular items that are charged or credited directly to equity, for example: (a) an adjustment to the opening balance of retained earnings resulting from either a change in accounting policy that is applied retrospectively or the correction of an error; and (b) amounts arising on initial recognition of the equity component of a compound financial instrument. [Refer: Deferred tax relating to items credited (charged) directly to equity; Retained earnings; Financial instruments, class [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2018-01-01 -Paragraph 81 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2018-03-01&anchor=para_81_a&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The amount of income tax relating to amounts recognised in other comprehensive income in relation to cash flow hedges. [Refer: Cash flow hedges [member]; Other comprehensive income] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2018-01-01 -Paragraph 81 -Subparagraph ab -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2018-03-01&anchor=para_81_ab&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 90 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_90&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The amount of income tax relating to amounts recognised in other comprehensive income in relation to remeasurements of defined benefit plans. [Refer: Other comprehensive income; Reserve of remeasurements of defined benefit plans; Defined benefit plans [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2018-01-01 -Paragraph 81 -Subparagraph ab -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2018-03-01&anchor=para_81_ab&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 90 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_90&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition Income Taxes [Abstract] + References No definition available. + Details
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- Definition Income tax relating to hedges of investments in equity instruments + References No definition available. + Details
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