Accounts Receivable - Schedule of accounts receivable (Details) - USD ($) $ in Millions |
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
Mar. 31, 2022 |
|---|---|---|---|---|
| Loans and Leases Receivable Disclosure [Line Items] | ||||
| Allowance for credit losses — third parties | $ (7) | $ (7) | $ (5) | $ (6) |
| Third Parties | ||||
| Loans and Leases Receivable Disclosure [Line Items] | ||||
| Trade accounts receivable | 1,964 | 1,671 | ||
| Other accounts receivable | 116 | 96 | ||
| Accounts receivable — third parties | 2,080 | 1,767 | ||
| Allowance for credit losses — third parties | (7) | (7) | ||
| Accounts receivable, net — third parties | 2,073 | 1,760 | ||
| Related Parties | ||||
| Loans and Leases Receivable Disclosure [Line Items] | ||||
| Accounts receivable, net — third parties | $ 136 | $ 161 |