Business segment information - Non-current assets by geography (Details) - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|---|
| Disclosure of operating segments [line items] | |||
| Non-current assets | $ 5,943 | $ 5,520 | $ 5,614 |
| United Kingdom | |||
| Disclosure of operating segments [line items] | |||
| Non-current assets | 608 | 465 | 525 |
| United States of America | |||
| Disclosure of operating segments [line items] | |||
| Non-current assets | 3,426 | 3,517 | 3,692 |
| Other | |||
| Disclosure of operating segments [line items] | |||
| Non-current assets | $ 1,909 | $ 1,538 | $ 1,397 |