intangible assets and goodwill - Business acquisitions - prior period (Details) - Business that is complimentary to existing lines $ in Millions	6 Months Ended
Jun. 30, 2020 CAD ($)
Business acquisition
Increase (decrease) in software	$ 32
Increase (decrease) in goodwill	(22)
Increase (decrease) in deferred income taxes	$ 10

The increase (decrease) in goodwill. [Refer: Goodwill]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2019-01-01
-Paragraph B67
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2019-en-r&anchor=para_B67_d&doctype=Appendix&subtype=B
-URIDate 2019-03-27

Name:	ifrs-full_ChangesInGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration