Supplemental financial information - Other income (expense), net (OI&E) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Text Block Supplement [Abstract]
Other income	[1]	$ 327	$ 201	$ 135
Other expense	[2]	(14)	(26)	(37)
Total		$ 313	$ 175	$ 98

[1] Other income includes royalty income, reversals of tax interest accruals, interest and lease income, as well as investment gains and losses.

[2] Other expense includes a portion of pension and other retiree benefit costs, currency gains and losses and miscellaneous items.