Assets held for sale and discontinued operations - Results of discontinued operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
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	$ 1,190	$ 179
Discontinued Operations | Building Envelope Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		645	1,775
Operating income		89	239
Gain on divestiture before income taxes		1,471	0
Income from discontinued operations before income tax expense		1,560	239
Income tax expense		(370)	(60)
Income from discontinued operations, net of income tax expense		$ 1,190	$ 179