Revenue - Revenue by Major 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
Companion animal
Revenue from External Customer [Line Items]
Revenue		1,263	1,076
Companion animal | U.S.
Revenue from External Customer [Line Items]
Revenue		774	658
Companion animal | International
Revenue from External Customer [Line Items]
Revenue		489	418
Livestock
Revenue from External Customer [Line Items]
Revenue		705	779
Livestock | U.S.
Revenue from External Customer [Line Items]
Revenue		246	275
Livestock | International
Revenue from External Customer [Line Items]
Revenue		459	504
Operating Segments | U.S.
Revenue from External Customer [Line Items]
Revenue		1,020	933
Operating Segments | International
Revenue from External Customer [Line Items]
Revenue	[1]	$ 948	$ 922

[1] Revenue denominated in euros was $203 million and $192 million for the three months ended March 31, 2022 and 2021, respectively.