Share repurchases - Narrative (Details) - March 2025 Normal Course Issuer Bid (NCIB) - CAD ($) shares in Millions, $ in Millions	Mar. 31, 2025	Mar. 03, 2025
Share Repurchase Program [Line Items]
Common Shares authorized to be repurchased		37.3
Share repurchase program, accrued tax liability	$ 7

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481520/505-30-50-4

Name:	srt_ShareRepurchaseProgramLineItems
Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration