Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator
Net income before allocation to noncontrolling interests	$ 558	$ 423
Less: Net loss attributable to noncontrolling interests	(1)	0
Net income attributable to Zoetis Inc.	$ 559	$ 423
Denominator
Weighted-average common shares outstanding	475,500,000	475,600,000
Common stock equivalents: stock options, RSUs, PSUs and DSUs	2,400,000	3,400,000
Weighted-average common and potential dilutive shares outstanding	477,900,000	479,000,000.0
Earnings per share attributable to Zoetis stockholders—basic (in dollars per share)	$ 1.18	$ 0.89
Earnings per share attributable to Zoetis stockholders—diluted (in dollars per share)	$ 1.17	$ 0.88
Antidilutive securities excluded from computation of earnings per share, amount	0