SHARE-BASED PAYMENTS - Carrying Amount of Share Based Payment Liabilities (Details) - CAD ($) $ in Millions	Mar. 31, 2025	Mar. 31, 2024
Disclosure of terms and conditions of share-based payment arrangement [line items]
Total carrying amount of share-based payments liabilities	$ 65.6	$ 61.2
Current portion	25.3	9.9
Share-based payments liabilities (Note 26)	40.3	51.3
DSU plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled plans	48.7	41.6
RSU plan
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled plans	6.5	9.1
PSU plan
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled plans	$ 10.4	$ 10.5

The amount of liabilities arising from share-based payment transactions. Share-based payment transactions are transactions in which the entity: (a) receives goods or services from the supplier of those goods or services (including an employee) in a share-based payment arrangement; or (b) incurs an obligation to settle the transaction with the supplier in a share-based payment arrangement when another group entity receives those goods or services. [Refer: Types of share-based payment arrangements [domain]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2024-01-01
-Paragraph 51
-Subparagraph b
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2024-en-r&anchor=para_51_b_i&doctype=Standard
-URIDate 2024-03-27

Name:	ifrs-full_LiabilitiesFromSharebasedPaymentTransactions2011
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant