Supplemental financial information - Amounts reclassified out of accumulated other comprehensive income (loss), net of taxes, to net income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net (OI&E)		$ 496	$ 440	$ 106
Provision for income taxes		(654)	(908)	(1,283)
Net income		4,799	6,510	8,749
Reclassification out of Accumulated Other Comprehensive Income | Net actuarial losses of defined benefit plans:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net (OI&E)	[1]	13	20	78
Provision for income taxes		(3)	(5)	(17)
Net income		10	15	61
Reclassification out of Accumulated Other Comprehensive Income | Prior service cost (credit) of defined benefit plans:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net (OI&E)	[1]	1	1	(1)
Provision for income taxes		0	0	0
Net income		$ 1	$ 1	$ (1)

[1] Detailed in Note 7