v3.25.1
Income Taxes (Reconciliation of Statutory Tax Rates) (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Reconciliation of Canadian statutory tax rates      
Pre-tax income before equity in net income of non-consolidated affiliates $ 839 $ 814 $ 790
Canadian statutory tax rate 25.00% 25.00% 25.00%
Provision at the Canadian statutory rate $ 210 $ 204 $ 198
Increase (decrease) for taxes on income (loss) resulting from:      
Exchange translation items 17 5 9
Exchange remeasurement of deferred income taxes (7) 1 (4)
Change in valuation allowances (55) 12 (36)
Tax credits (35) (36) (36)
Expense (income) items not subject to tax 9 (9) (13)
State tax expense, net (1) (2) 3
Enacted tax rate changes 0 1 3
Tax rate differences on foreign earnings 48 36 19
Uncertain tax positions (24) 19 3
Prior year adjustments (7) (18) (13)
Income tax settlements 7 0 0
Non-deductible expenses and other, net (3) 5 14
Income tax provision $ 159 $ 218 $ 147
Effective tax rate 19.00% 27.00% 19.00%