Segment and Geographic Information - Schedule of Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Revenues from External Customers and Long-Lived Assets [Line Items] | ||
| Long-lived assets | $ 1,220 | $ 714 |
| United Kingdom | ||
| Revenues from External Customers and Long-Lived Assets [Line Items] | ||
| Long-lived assets | 628 | 444 |
| United States | ||
| Revenues from External Customers and Long-Lived Assets [Line Items] | ||
| Long-lived assets | 438 | 197 |
| Other countries | ||
| Revenues from External Customers and Long-Lived Assets [Line Items] | ||
| Long-lived assets | $ 154 | $ 73 |