Revenue - Revenue by 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
Dogs and Cats
Revenue from External Customer [Line Items]
Revenue	1,303	1,161	2,502	2,177
Horses
Revenue from External Customer [Line Items]
Revenue	63	68	127	128
Cattle
Revenue from External Customer [Line Items]
Revenue	328	342	692	741
Swine
Revenue from External Customer [Line Items]
Revenue	144	161	298	351
Poultry
Revenue from External Customer [Line Items]
Revenue	121	134	245	265
Fish
Revenue from External Customer [Line Items]
Revenue	47	39	91	76
Sheep and other
Revenue from External Customer [Line Items]
Revenue	28	23	47	45
Livestock
Revenue from External Customer [Line Items]
Revenue	668	699	1,373	1,478
Companion animal
Revenue from External Customer [Line Items]
Revenue	1,366	1,229	2,629	2,305
Other pharmaceuticals
Revenue from External Customer [Line Items]
Revenue	$ 265	$ 248	$ 519	$ 474