Income taxes - Valuation Allowance Activity (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 28, 2025 |
Dec. 29, 2024 |
|
| Valuation Allowance [Roll Forward] | ||
| Beginning of year | $ 1,638 | $ 1,149 |
| Provision | 129 | 451 |
| Utilization | (70) | 0 |
| Foreign currency translation | 90 | (46) |
| Net acquisitions / (dispositions/liquidations) | 50 | 84 |
| End of year | $ 1,837 | $ 1,638 |