v3.25.4
Cover - USD ($)
 12 Months Ended
Dec. 31, 2025
Jun. 30, 2025
Cover [Abstract]    
Document Type 10-K  
Document Annual Report true  
Document Period End Date Dec. 31, 2025  
Current Fiscal Year End Date --12-31  
Document Transition Report false  
Entity File Number 1-42542  
Registrant Name Amrize Ltd  
Entity Incorporation, State or Country Code V8  
Entity Tax Identification Number 98-1807904  
Entity Address, Address Line One Grafenauweg 8  
Entity Address, City or Town Zug  
Entity Address, Country CH  
Entity Address, Postal Zip Code 6300  
Country Region 41  
City Area Code 41  
Local Phone Number 562 3490  
Title of 12(b) Security Ordinary Shares, par value $0.01 per share  
Trading Symbol AMRZ  
Security Exchange Name NYSE  
Entity Well-known Seasoned Issuer No  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
ICFR Auditor Attestation Flag false  
Document Financial Statement Error Correction [Flag] false  
Entity Shell Company false  
Entity Public Float   $ 27,362,509,572
Entity Common Stock, Shares Outstanding 553,082,525  
Documents Incorporated by Reference INCORPORATION BY REFERENCE
Part III hereof incorporates by reference portions of the registrant’s definitive proxy statement related to its the 2026
Annual Meeting of Shareholders (the “Proxy Statement”)		  
Central Index Key 0002035989  
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus FY