Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Statement of comprehensive income [abstract]
Currency translation differences, taxes	$ (17)	$ (26)
Change in fair value of available-for-sale financial instruments, taxes	0	0
Change in fair value of marketable equity securities, taxes	(3)	(1)
Remeasurements of retirement benefit plans, tax	$ 29	$ (31)

The amount of income tax relating to amounts recognised in other comprehensive income in relation to available-for-sale financial assets. [Refer: Financial assets available-for-sale; Other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2021-01-01
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-IssueDate 2020-01-01
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-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2021-01-01
-Name IAS
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-IssueDate 2020-01-01
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-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2017-en-b&anchor=para_90&doctype=Standard&forcepdf=true
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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to exchange differences on the translation of financial statements of foreign operations. [Refer: Other comprehensive income; Reserve of exchange differences on translation]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2020-01-01
-Paragraph 81
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-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_90&doctype=Standard
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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: Other comprehensive income; Reserve of gains and losses from investments in equity instruments]

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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]]

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- References

No definition available.

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