Acquisitions and divestitures - Summary of Total Consideration for ChemoCentryx Inc (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Oct. 20, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill	$ 18,629	$ 15,529		$ 14,890
ChemoCentryx, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents			$ 86
Marketable securities			235
Inventories			41
Goodwill			649
Other liabilities, net			(83)
Deferred tax liability, net			(502)
Total assets acquired, net			3,925
ChemoCentryx, Inc. | Developed-product-technology rights
Business Acquisition [Line Items]
Finite-lived intangible assets – developed-product-technology rights			$ 3,499