v3.26.1
INCOME TAXES - Reconciliation of Income Taxes (Details) - CAD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Income Tax [Abstract]    
Earnings before income taxes $ 400.2 $ 513.7
Canadian statutory income tax rates (in percent) 26.50% 26.50%
Income taxes at Canadian statutory rates $ 106.1 $ 136.2
Effect of differences in tax rates in other jurisdictions (13.6) 1.8
Tax benefits not previously recognized and unrecognized tax benefits (0.5) (6.8)
Non-taxable gain on fair value remeasurement of SIMCOM 0.0 (21.9)
Non-deductible expenses 5.5 0.0
Tax impact on after tax profit of equity accounted investees (17.7) (18.5)
Prior years' tax adjustments (1.9) 2.8
Other (0.4) 5.1
Income tax expense $ 77.5 $ 98.7
Effective tax rate (in percent) 19.00% 19.00%