Revenue - Revenue by Major Species (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022
Revenue from External Customer [Line Items]
Revenue	$ 2,151	$ 2,002	$ 6,331		$ 6,040
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue	21	23	58		59
Companion animal
Revenue from External Customer [Line Items]
Revenue	1,414	1,271	4,128		3,900
Companion animal | U.S.
Revenue from External Customer [Line Items]
Revenue	908	819	2,588		2,488
Companion animal | International
Revenue from External Customer [Line Items]
Revenue	506	452	1,540		1,412
Livestock
Revenue from External Customer [Line Items]
Revenue	716	708	2,145		2,081
Livestock | U.S.
Revenue from External Customer [Line Items]
Revenue	266	271	756		713
Livestock | International
Revenue from External Customer [Line Items]
Revenue	450	437	1,389		1,368
Operating Segments | U.S.
Revenue from External Customer [Line Items]
Revenue	1,174	1,090	3,344		3,201
Operating Segments | International
Revenue from External Customer [Line Items]
Revenue	$ 956	$ 889	$ 2,929	[1]	$ 2,780	[1]

[1] Revenue denominated in euros was $627 million and $590 million for the nine months ended September 30, 2023 and 2022, respectively.