Revenue - Revenue by Product (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
Vaccines
Revenue from External Customer [Line Items]
Revenue	405	413
Parasiticides
Revenue from External Customer [Line Items]
Revenue	459	390
Anti-infectives
Revenue from External Customer [Line Items]
Revenue	285	321
Dermatology
Revenue from External Customer [Line Items]
Revenue	311	248
Other pharmaceuticals
Revenue from External Customer [Line Items]
Revenue	254	226
Medicated feed additives
Revenue from External Customer [Line Items]
Revenue	98	112
Animal health diagnostics
Revenue from External Customer [Line Items]
Revenue	98	89
Other non-pharmaceuticals
Revenue from External Customer [Line Items]
Revenue	58	56
Total products and services
Revenue from External Customer [Line Items]
Revenue	$ 1,968	$ 1,855