Goodwill and other intangible assets - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Finite-lived intangible assets:
Gross carrying amounts	$ 55,080	$ 55,229
Accumulated amortization	(24,858)	(23,806)
Other intangible assets, net	30,222	31,423
Indefinite-lived intangible assets:
Identifiable intangible assets	56,230	56,447
Accumulated amortization	(24,858)	(23,806)
Intangible assets, net	31,372	32,641
In-process research and development
Indefinite-lived intangible assets:
Indefinite-lived intangible assets	1,150	1,218
Developed-product-technology rights
Finite-lived intangible assets:
Gross carrying amounts	48,625	48,631
Accumulated amortization	(19,184)	(18,049)
Other intangible assets, net	29,441	30,582
Licensing rights
Finite-lived intangible assets:
Gross carrying amounts	3,864	3,865
Accumulated amortization	(3,297)	(3,265)
Other intangible assets, net	567	600
Marketing-related rights
Finite-lived intangible assets:
Gross carrying amounts	1,203	1,339
Accumulated amortization	(1,148)	(1,264)
Other intangible assets, net	55	75
Research and development technology rights
Finite-lived intangible assets:
Gross carrying amounts	1,388	1,394
Accumulated amortization	(1,229)	(1,228)
Other intangible assets, net	$ 159	$ 166