Related party - Schedule of Net Parent Investment (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Related Party Transactions [Abstract] | |||
| Net transfers to Parent as reflected on the unaudited condensed consolidated statements of cash flows | $ (91) | $ (304) | $ (20) |
| Equity contribution from Holcim related to the settlement of Related-party notes payable | 1,999 | 0 | 0 |
| Other non-cash activities with Parent, net | 25 | 31 | 3 |
| Net transfers from (to) Holcim as reflected on the consolidated statements of equity | $ 1,933 | $ (273) | $ (17) |