v3.25.4

Organization and basis of presentation - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) segment shares	Dec. 31, 2024 USD ($)	Jun. 23, 2025 shares
Business Combination [Line Items]
Number of reportable segments | segment	2
Common stock, outstanding (in shares)	553,082,525		566,875,513
Treasury stock (in shares)	13,792,988		13,793,444
Related Party
Business Combination [Line Items]
Various transaction costs | $	$ 11	$ 15
Holcim Ltd
Business Combination [Line Items]
Common stock, outstanding (in shares)			566,875,513
Holcim Ltd | Amrize Ltd | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Business Combination [Line Items]
Equity interest disposed			100.00%
Number of shares issued (in shares)			553,082,069

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