v3.25.4

Summary of significant accounting policies - Schedule of Lease Terms (Details)	Dec. 31, 2025
Rail fleet and equipment
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	25 years
Machinery and equipment | Minimum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	10 years
Machinery and equipment | Maximum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	30 years
Buildings and installations | Minimum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	20 years
Buildings and installations | Maximum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	35 years
Furniture and fixtures | Minimum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	3 years
Furniture and fixtures | Maximum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	10 years
Land fleet equipment | Minimum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	3 years
Land fleet equipment | Maximum
Lessee, Lease, Description [Line Items]
Estimated useful lives of leased assets	15 years

X

- Definition

Lessee, Operating Lease, Asset Useful Life

+ References

No definition available.

+ Details

Name:	holcim_LesseeOperatingLeaseAssetUsefulLife
Namespace Prefix:	holcim_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-7A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeLeaseDescriptionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_RailroadTransportationEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MachineryAndEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingAndBuildingImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_FurnitureAndFixturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=holcim_LandFleetEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: