Capital Stock - Schedule of Share-based Compensation Expense by Category (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Share-Based Compensation Expense [Line Items] | ||
| Total share-based compensation expense | $ 1.7 | $ 13.4 |
| General and administration | ||
| Share-Based Compensation Expense [Line Items] | ||
| Total share-based compensation expense | 2.8 | 13.4 |
| Restructuring and other | ||
| Share-Based Compensation Expense [Line Items] | ||
| Total share-based compensation expense | $ (1.1) | $ 0.0 |