Revenue - Revenue by 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
Dogs and Cats
Revenue from External Customer [Line Items]
Revenue	1,481	1,384
Horses
Revenue from External Customer [Line Items]
Revenue	65	66
Livestock
Revenue from External Customer [Line Items]
Revenue	645	720
Cattle
Revenue from External Customer [Line Items]
Revenue	358	391
Swine
Revenue from External Customer [Line Items]
Revenue	111	127
Poultry
Revenue from External Customer [Line Items]
Revenue	106	139
Fish
Revenue from External Customer [Line Items]
Revenue	53	45
Sheep and other
Revenue from External Customer [Line Items]
Revenue	17	18
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue	$ 29	$ 20