Revenue - Revenue by Product (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenue from External Customer [Line Items]
Revenue	$ 2,400	$ 2,388	$ 7,080	$ 6,939
Total products and services
Revenue from External Customer [Line Items]
Revenue	2,377	2,367	6,994	6,880
Parasiticides
Revenue from External Customer [Line Items]
Revenue	564	530	1,799	1,634
Vaccines
Revenue from External Customer [Line Items]
Revenue	496	468	1,447	1,365
Dermatology
Revenue from External Customer [Line Items]
Revenue	472	453	1,325	1,234
Anti-infectives
Revenue from External Customer [Line Items]
Revenue	284	274	752	819
Pain and sedation
Revenue from External Customer [Line Items]
Revenue	204	219	631	634
Other pharmaceutical
Revenue from External Customer [Line Items]
Revenue	178	169	509	478
Animal health diagnostics
Revenue from External Customer [Line Items]
Revenue	110	101	323	286
Other non-pharmaceutical
Revenue from External Customer [Line Items]
Revenue	64	62	193	188
Medicated feed additives
Revenue from External Customer [Line Items]
Revenue	5	91	15	242
Contract manufacturing & human health
Revenue from External Customer [Line Items]
Revenue	$ 23	$ 21	$ 86	$ 59