Other income (expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other Income and Expenses [Abstract]
Investment and interest income	$ 23	$ 43
Foreign exchange gains (losses)	95	(75)
License fee income	25	25
Net periodic pension and OPEB income (cost), excluding service cost	111	333
Gains (losses) on securities	25	(58)
Miscellaneous income (loss)	46	(46)
Total	325	222
Foreign Plan
Other income (expense) [Line Items]
Gain on remeasurement of pension obligations	$ 0	$ 254