Share capital - Stock options excluded from the calculation of diluted loss per share (Details) - shares shares in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Disclosure of classes of share capital [abstract]
Stock options, performance share units, deferred share units excluded from the calculation of diluted loss per share (in shares)	5.1	9.9

Number of potential ordinary shares that are antidilutive in the period presented.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 33
-IssueDate 2023-01-01
-Paragraph 70
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=33&code=ifrs-tx-2023-en-r&anchor=para_70_c&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_NumberOfPotentialOrdinarySharesThatAreAntidilutiveInPeriodPresented
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration