Financial instruments - Aging analysis of trade accounts receivable (Details) - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Disclosure of detailed information about financial instruments [line items] | ||
| Current trade receivables | $ 186 | $ 239 |
| Sales taxes receivable | 27 | 27 |
| Other | 31 | 28 |
| Total trade and other current receivables | 244 | 294 |
| Current | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Current trade receivables | 129 | 175 |
| Not Later Than 30 Days | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Current trade receivables | 48 | 62 |
| Later Than 30 Days And Not Later Than 60 Days | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Current trade receivables | 6 | 2 |
| Later Than 60 Days | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Current trade receivables | $ 4 | $ 0 |