Derivative financial instruments and debt excluding lease liabilities - Comparison of the Fair Value with the Carrying Amount of Debt Excluding Lease Liabilities (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Financial Instruments [Abstract] | ||
| Carrying amount | $ 43,449 | $ 46,710 |
| Fair value | $ 39,681 | $ 43,142 |