Income Taxes - Components of Income Tax Expense (Recovery) Recognized in Other Comprehensive Income ("OCI") (Detail) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Major components of tax expense (income) [abstract]
Current income tax expense (recovery)	$ (323)	$ (3)
Deferred income tax expense (recovery)	(863)	(61)
Total income tax expense (recovery)	$ (1,186)	$ (64)

The amount of income tax relating to amounts recognised in other comprehensive income. [Refer: Other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2022-03-24
-Paragraph 81
-Subparagraph ab
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2022-en-r&anchor=para_81_ab&doctype=Standard
-URIDate 2022-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2022-03-24
-Paragraph 90
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_90&doctype=Standard
-URIDate 2022-03-24

Name:	ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration