v3.25.4

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)

X
- Definition Equity Contribution From Parent + References No definition available. + Details
Name: | holcim_EquityContributionFromParent
Namespace Prefix: | holcim_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Net Transfers To (From) Parent + References No definition available. + Details
Name: | holcim_NetTransfersToFromParent
Namespace Prefix: | holcim_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Other Non-Cash Activities With Parent, Net + References No definition available. + Details
Name: | holcim_OtherNonCashActivitiesWithParentNet
Namespace Prefix: | holcim_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Transfers To Parent, Net + References No definition available. + Details
Name: | holcim_TransfersToParentNet
Namespace Prefix: | holcim_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RelatedPartyTransactionsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration