Revenue - Revenue by Major Species (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021
Revenue from External Customer [Line Items]
Revenue	$ 2,052		$ 1,948		$ 4,038		$ 3,819
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue	18		20		36		36
Companion animal
Revenue from External Customer [Line Items]
Revenue	1,366		1,229		2,629		2,305
Companion animal | U.S.
Revenue from External Customer [Line Items]
Revenue	895		794		1,669		1,452
Companion animal | International
Revenue from External Customer [Line Items]
Revenue	471		435		960		853
Livestock
Revenue from External Customer [Line Items]
Revenue	668		699		1,373		1,478
Livestock | U.S.
Revenue from External Customer [Line Items]
Revenue	196		210		442		485
Livestock | International
Revenue from External Customer [Line Items]
Revenue	472		489		931		993
Operating Segments | U.S.
Revenue from External Customer [Line Items]
Revenue	1,091		1,004		2,111		1,937
Operating Segments | International
Revenue from External Customer [Line Items]
Revenue	$ 943	[1]	$ 924	[1]	$ 1,891	[2]	$ 1,846	[2]

[1] Revenue denominated in euros was $204 million and $209 million for the three months ended June 30, 2022 and 2021, respectively.

[2] Revenue denominated in euros was $407 million and $401 million for the six months ended June 30, 2022 and 2021, respectively.