Revenue - Revenue by Major Species (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024		Jun. 30, 2023
Revenue from External Customer [Line Items]
Revenue	$ 2,361	$ 2,180	$ 4,551		$ 4,180
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue	18	20	38		37
Companion animal
Revenue from External Customer [Line Items]
Revenue	1,649	1,489	3,099		2,714
Companion animal | U.S.
Revenue from External Customer [Line Items]
Revenue	1,080	959	1,978		1,680
Companion animal | International
Revenue from External Customer [Line Items]
Revenue	569	530	1,121		1,034
Livestock
Revenue from External Customer [Line Items]
Revenue	694	671	1,414		1,429
Livestock | U.S.
Revenue from External Customer [Line Items]
Revenue	228	206	493		490
Livestock | International
Revenue from External Customer [Line Items]
Revenue	466	465	921		939
Operating Segments | U.S.
Revenue from External Customer [Line Items]
Revenue	1,308	1,165	2,471		2,170
Operating Segments | International
Revenue from External Customer [Line Items]
Revenue	$ 1,035	$ 995	$ 2,042	[1]	$ 1,973	[1]

[1] Revenue denominated in euros was $460 million and $421 million for the six months ended June 30, 2024 and 2023, respectively.