The amount of the estimated financial effect of contingent liabilities. [Refer: Contingent liabilities [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2020-01-01
-Paragraph 86
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2020-en-r&anchor=para_86_a&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_EstimatedFinancialEffectOfContingentLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

contingent liabilities (Details) - CAD ($) $ in Millions	12 Months Ended
contingent liabilities (Details) - CAD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Indemnification obligation
Estimated financial effect of contingent liabilities
Claims and lawsuits \| Area Code 867 blocking claim
Claims and lawsuits
Damages sought	135
Indemnification obligations
Indemnification obligation
Estimated financial effect of contingent liabilities	$ 0