Reinsurance - Schedule of Reinsurance Expenses and Benefits (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Insurance Contracts [Abstract]
Recovered claims and benefits	$ 2,182	$ 1,955
Commissions	69	70
Reserve adjustments	22	26
Operating expenses and other	80	80
Total reinsurance (expenses) recoveries	2,353	2,131
Loss recognized from entrance of reinsurance agreement	$ 66	$ 0

The amount of income from contracts with reinsurers.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Note Expiry date 2021-01-01
-Name IFRS
-Number 4
-IssueDate 2019-01-01
-Paragraph IG24
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2019-en-b&anchor=para_IG24_b&doctype=Implementation%20Guidance&book=b
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Note Expiry date 2021-01-01
-Name IFRS
-Number 4
-IssueDate 2019-01-01
-Paragraph 37
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2019-en-b&anchor=para_37_b&doctype=Standard&book=b
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Note Expiry date 2021-01-01
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 85
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-b&anchor=para_85&doctype=Standard&book=b
-URIDate 2019-03-27

Name:	ifrs-full_IncomeFromContractsWithReinsurers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration