Revenue - Revenue by Species (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from External Customer [Line Items]
Revenue	$ 1,986	$ 1,871
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue	18	16
Dogs and Cats
Revenue from External Customer [Line Items]
Revenue	1,199	1,016
Horses
Revenue from External Customer [Line Items]
Revenue	64	60
Cattle
Revenue from External Customer [Line Items]
Revenue	364	399
Swine
Revenue from External Customer [Line Items]
Revenue	154	190
Poultry
Revenue from External Customer [Line Items]
Revenue	124	131
Fish
Revenue from External Customer [Line Items]
Revenue	44	37
Sheep and other
Revenue from External Customer [Line Items]
Revenue	19	22
Livestock
Revenue from External Customer [Line Items]
Revenue	705	779
Companion animal
Revenue from External Customer [Line Items]
Revenue	1,263	1,076
Other pharmaceuticals
Revenue from External Customer [Line Items]
Revenue	$ 254	$ 226