Accumulated other comprehensive loss - Reclassification out of accumulated other comprehensive income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other nonoperating income, net	$ (12)	$ (62)	$ 17	$ (246)
Income tax benefit	428	531	795	942
Total	(1,503)	(1,376)	(2,728)	(2,789)
Reclassifications from Accumulated other comprehensive loss to income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total	(4)	(6)	(21)	12
Reclassifications from Accumulated other comprehensive loss to income | Cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of product revenues	(2)	1	(3)	23
Income tax benefit	0	0	0	(3)
Total	(2)	1	(3)	20
Reclassifications from Accumulated other comprehensive loss to income | Pension and other postretirement plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other nonoperating income, net	(2)	(6)	(19)	(8)
Income tax benefit	0	(1)	1	0
Total	$ (2)	$ (7)	$ (18)	$ (8)