Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 19,503	$ 15,891	$ 16,516
Total other comprehensive income (loss), net of tax	(651)	637	(904)
Ending balance	19,494	19,503	15,891
Foreign currency translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,782)	(2,328)	(1,508)
Gains (losses)	(535)	32	(794)
Less: Tax provision /(benefit)	21	(21)	26
Net gains (losses) on foreign currency translation	(556)	53	(820)
(Gains) losses reclassified to earnings	28	493	0
Less: Tax provision /(benefit)	0	0	0
Net (gains) losses reclassified to earnings	28	493	0
Total other comprehensive income (loss), net of tax	(528)	546	(820)
Ending balance	(2,310)	(1,782)	(2,328)
Pension and other postretirement benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(49)	(39)	(62)
Gains (losses)	0	1	33
Less: Tax provision /(benefit)	0	0	5
Net gains (losses) on foreign currency translation	0	1	28
(Gains) losses reclassified to earnings	(14)	(12)	(6)
Less: Tax provision /(benefit)	(2)	(1)	(1)
Net (gains) losses reclassified to earnings	(12)	(11)	(5)
Total other comprehensive income (loss), net of tax	(12)	(10)	23
Ending balance	(61)	(49)	(39)
Derivative financial instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	67	28	(3)
Gains (losses)	64	48	375
Less: Tax provision /(benefit)	27	11	86
Net gains (losses) on foreign currency translation	37	37	289
(Gains) losses reclassified to earnings	(207)	3	(340)
Less: Tax provision /(benefit)	(57)	1	(82)
Net (gains) losses reclassified to earnings	(150)	2	(258)
Total other comprehensive income (loss), net of tax	(113)	39	31
Ending balance	(46)	67	28
Available-for-sale securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(56)	(118)	20
Gains (losses)	(2)	72	(179)
Less: Tax provision /(benefit)	0	11	(37)
Net gains (losses) on foreign currency translation	(2)	61	(142)
(Gains) losses reclassified to earnings	4	1	5
Less: Tax provision /(benefit)	0	0	1
Net (gains) losses reclassified to earnings	4	1	4
Total other comprehensive income (loss), net of tax	2	62	(138)
Ending balance	(54)	(56)	(118)
Accumulated other comprehensive income (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,820)	(2,457)	(1,553)
Ending balance	$ (2,471)	$ (1,820)	$ (2,457)