Acquisitions, Divestitures and Other Arrangements - Summary of Amounts Recognized for Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Dec. 31, 2023	Aug. 01, 2023	Jan. 03, 2023	Dec. 31, 2022	Dec. 31, 2021	Aug. 27, 2021
Business Acquisition [Line Items]
Goodwill	$ 5,094			$ 5,993	$ 6,172
NutriQuest, LLC
Business Acquisition [Line Items]
Inventories			$ 3
Total identifiable net assets			56
Goodwill			3
Total consideration transferred			59
NutriQuest, LLC | Marketed products
Business Acquisition [Line Items]
Definite-lived intangible assets			29
NutriQuest, LLC | Acquired IPR&D
Business Acquisition [Line Items]
Definite-lived intangible assets			9
NutriQuest, LLC | Other
Business Acquisition [Line Items]
Definite-lived intangible assets			$ 15
NutriQuest Brazil
Business Acquisition [Line Items]
Inventories		$ 3
Definite-lived intangible assets		15
Total identifiable net assets		18
Goodwill		1
Total consideration transferred		$ 19
KindredBio
Business Acquisition [Line Items]
Total identifiable net assets						$ 380
Goodwill						35
Cash and cash equivalents						31
Other net working capital						13
Property and equipment						33
Deferred income taxes, net						(30)
Settlement of liability related to previous license agreement						29
Total consideration transferred						444
KindredBio | Acquired IPR&D
Business Acquisition [Line Items]
Intangible assets, primarily acquired IPR&D						$ 333