Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator
Net income before allocation to noncontrolling interests	$ 552	$ 479	$ 1,621	$ 1,278
Less: Net loss attributable to noncontrolling interests	0	0	(2)	(1)
Net income attributable to Zoetis Inc.	$ 552	$ 479	$ 1,623	$ 1,279
Denominator
Weighted-average common shares outstanding	474,000,000.0	475,500,000	474,800,000	475,500,000
Common stock equivalents: stock options, RSUs, PSUs and DSUs	2,300,000	3,000,000.0	2,300,000	3,000,000.0
Weighted-average common and potential dilutive shares outstanding	476,300,000	478,500,000	477,100,000	478,500,000
Earnings per share attributable to Zoetis stockholders—basic (in dollars per share)	$ 1.16	$ 1.01	$ 3.42	$ 2.69
Earnings per share attributable to Zoetis stockholders—diluted (in dollars per share)	$ 1.16	$ 1.00	$ 3.40	$ 2.67
Antidilutive securities excluded from computation of earnings per share, amount	0	0	0	0