Asset Impairment, Restructuring and Other Special Charges - Component of Asset Impairment, Restructuring and Other Special Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Restructuring charges (credits):
Severance and other costs	$ 0	$ (2)	$ (9)	$ 26
Facility exit costs	0	0	2	0
Acquisition related charges:
Transaction and integration costs	27	30	77	141
Non-cash and other items:
Asset impairment	0	50	59	63
Asset write-down	(1)	6	27	275
Net periodic benefit income	0	(9)	0	(26)
Settlements and other	0	36	2	39
Total expense	26	111	158	518
Litigation settlement charges		$ 8		$ 8
KindredBio
Non-cash and other items:
Measurement period adjustment related to settlement of preexisting liability			2
Variable Interest Entity, Primary Beneficiary | BexCaFe, LLC | Intangible assets, primarily acquired in-process research and development (IPR&D)
Non-cash and other items:
Asset impairment	$ 59		$ 59