Financial instruments - Schedule of financial assets and liabilities measured at fair value (Details) - USD ($) $ in Millions |
Dec. 31, 2025 |
Jun. 30, 2025 |
Dec. 31, 2024 |
|---|---|---|---|
| Valuation techniques based on observable market input (Level 2) | |||
| Disclosure of detailed information about financial instruments [line items] | |||
| Derivative assets | $ 681 | $ 733 | $ 469 |
| Derivative liabilities | (261) | (275) | (540) |
| Financial assets/(liabilities) | 420 | 458 | (71) |
| Valuation techniques based on unobservable market input (Level 3) | |||
| Disclosure of detailed information about financial instruments [line items] | |||
| Financial assets/(liabilities) | (155) | (151) | (82) |
| Financial assets - other | 74 | 75 | 337 |
| Financial liabilities - other | $ (229) | $ (226) | $ (419) |