Derivative instruments (Summary of Income and Expense Line Items) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Total revenues	$ 6,652	$ 6,706	$ 19,484	$ 19,133
Other income (expense), net	100	73	(747)	97
Interest expense, net	(368)	(296)	(991)	(862)
Interest rate swap agreements
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on fair value hedging relationships, Hedged items	240	54	734	195
Gains (losses) on fair value hedging relationships, Derivatives designated as hedging instruments	(220)	(31)	(670)	(128)
Reclassification out of Accumulated Other Comprehensive Income | Cash flow hedges | Cross-currency swap contracts
Derivative Instruments, Gain (Loss) [Line Items]
Other income (expense), net	(198)	(104)	(461)	(190)
Product sales
Derivative Instruments, Gain (Loss) [Line Items]
Total revenues	6,237	6,320	18,249	18,026
Product sales | Reclassification out of Accumulated Other Comprehensive Income | Cash flow hedges | Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total revenues	$ 69	$ (5)	$ 149	$ (24)