v3.26.1
INCOME TAXES - Components of the Provision for the Income Tax Expense (Details) - CAD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Current income tax expense :    
Current year $ 36.2 $ 56.7
Prior years' tax adjustments 19.4 (2.7)
Deferred income tax expense:    
Tax benefit not previously recognized used to reduce the deferred tax expense (0.5) (6.8)
Origination and reversal of temporary differences 22.4 51.5
Income tax expense $ 77.5 $ 98.7