Revenue - Revenue by 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
Dogs and Cats
Revenue from External Customer [Line Items]
Revenue	1,581	1,424	2,965	2,577
Horses
Revenue from External Customer [Line Items]
Revenue	68	65	134	137
Cattle
Revenue from External Customer [Line Items]
Revenue	350	329	741	728
Swine
Revenue from External Customer [Line Items]
Revenue	130	133	257	275
Poultry [Member]
Revenue from External Customer [Line Items]
Revenue	132	131	271	270
Fish
Revenue from External Customer [Line Items]
Revenue	62	52	107	101
Sheep and other
Revenue from External Customer [Line Items]
Revenue	20	26	38	55
Livestock
Revenue from External Customer [Line Items]
Revenue	694	671	1,414	1,429
Companion animal
Revenue from External Customer [Line Items]
Revenue	1,649	1,489	3,099	2,714
Other pharmaceutical
Revenue from External Customer [Line Items]
Revenue	$ 153	$ 170	$ 309	$ 348