Related Party Transactions - Schedule of Related Party Transactions with Key Management Personnel (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Disclosure Of Key Management Personnel Stock Compensation Expense [Abstract] | |||
| Salaries and other short term employee benefits to whole-time directors and executive officers | $ 14 | $ 14 | $ 14 |
| Commission and other benefits to non-executive / independent directors | 2 | 2 | 2 |
| Total compensation | $ 16 | $ 16 | $ 16 |