Segment information - Schedule of Reconciliation of Assets (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Segment Reporting [Line Items]
Total Assets	$ 24,603	$ 24,209
Operating Segments
Segment Reporting [Line Items]
Total Assets	23,185	21,912
Operating Segments \| Building Materials
Segment Reporting [Line Items]
Total Assets	15,752	14,939
Operating Segments \| Building Envelope
Segment Reporting [Line Items]
Total Assets	7,433	6,973
Reconciling items
Segment Reporting [Line Items]
Total Assets	$ 1,418	$ 2,297

Amount of asset recognized for present right to economic benefit.

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+ Details

- 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.

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+ Details