Tax - Schedule of Income Tax Paid By Individual Jurisdiction (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Income Tax Paid, by Individual Jurisdiction [Line Items] | |||
| Total taxes paid, net of refunds | $ 162.5 | $ 184.4 | $ 93.1 |
| United Kingdom [Member] | |||
| Income Tax Paid, by Individual Jurisdiction [Line Items] | |||
| Total taxes paid, net of refunds | 142.6 | 169.5 | 78.3 |
| Brazil [Member] | |||
| Income Tax Paid, by Individual Jurisdiction [Line Items] | |||
| Total taxes paid, net of refunds | 0.0 | 0.0 | 8.6 |
| Other jurisdictions [Member] | |||
| Income Tax Paid, by Individual Jurisdiction [Line Items] | |||
| Total taxes paid, net of refunds | $ 19.9 | $ 14.9 | $ 6.2 |