Stockholders' equity (Components of AOCI) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Increase (Decrease) in AOCI [Roll Forward]
Balance as of beginning of period	$ 2,419	$ 916	$ 6,700	$ 8,247	$ 6,700	$ 9,409
Foreign currency translation adjustments	(109)			(35)	(225)	(60)
Balance as of end of period	3,653	2,419	916	8,217	3,653	8,217
Foreign currency translation
Increase (Decrease) in AOCI [Roll Forward]
Balance as of beginning of period	(960)	(895)	(844)		(844)
Foreign currency translation adjustments		(65)	(51)	(109)
Income taxes		0	0	0
Balance as of end of period	(1,069)	(960)	(895)		(1,069)
Cash flow hedges
Increase (Decrease) in AOCI [Roll Forward]
Balance as of beginning of period	301	145	61		61
Unrealized gains		67	56	45
Reclassification adjustments to income		132	51	129
Income taxes		(43)	(23)	(36)
Balance as of end of period	439	301	145		439
Available-for-sale securities
Increase (Decrease) in AOCI [Roll Forward]
Balance as of beginning of period	0	0	0		0
Unrealized gains		0	0	0
Reclassification adjustments to income		0	0	0
Income taxes		0	0	0
Balance as of end of period	0	0	0		0
Other
Increase (Decrease) in AOCI [Roll Forward]
Balance as of beginning of period	(13)	(13)	(13)		(13)
Unrealized gains		0	0	0
Other				(9)
Balance as of end of period	(22)	(13)	(13)		(22)
AOCI
Increase (Decrease) in AOCI [Roll Forward]
Balance as of beginning of period	(672)	(763)	(796)	(868)	(796)	(985)
Foreign currency translation adjustments		(65)	(51)	(109)
Unrealized gains		67	56	45
Reclassification adjustments to income		132	51	129
Other				(9)
Income taxes		(43)	(23)	(36)
Balance as of end of period	$ (652)	$ (672)	$ (763)	$ (808)	$ (652)	$ (808)