Assets held for sale and discontinued operations - Results of discontinued operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations, net of income tax expense	$ 0	$ 0	$ 1,190
Discontinued Operations | Building Envelope Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues			645
Operating income			89
Gain on divestiture before income taxes			1,471
Income from discontinued operations before income tax expense			1,560
Income tax expense			(370)
Income from discontinued operations, net of income tax expense			$ 1,190