Revenue - Revenue by Major Species (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Revenue from External Customer [Line Items]
Revenue		$ 2,220	$ 2,190
Companion animal
Revenue from External Customer [Line Items]
Revenue		1,546	1,450
Companion animal | U.S.
Revenue from External Customer [Line Items]
Revenue		973	898
Companion animal | International
Revenue from External Customer [Line Items]
Revenue		573	552
Livestock
Revenue from External Customer [Line Items]
Revenue		645	720
Livestock | U.S.
Revenue from External Customer [Line Items]
Revenue		210	265
Livestock | International
Revenue from External Customer [Line Items]
Revenue		435	455
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue		29	20
Operating Segments | U.S.
Revenue from External Customer [Line Items]
Revenue		1,183	1,163
Operating Segments | International
Revenue from External Customer [Line Items]
Revenue	[1]	$ 1,008	$ 1,007

[1] Revenue denominated in euros was $227 million and $223 million for the three months ended March 31, 2025 and 2024, respectively.