Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator
Net income before allocation to noncontrolling interests	$ 479	$ 433	$ 1,278	$ 1,116
Less: Net loss attributable to noncontrolling interests	0	0	(1)	0
Net income attributable to Zoetis Inc.	$ 479	$ 433	$ 1,279	$ 1,116
Denominator
Weighted-average common shares outstanding	475,500	477,800	475,500	478,700
Common stock equivalents: stock options, RSUs, PSUs and DSUs	3,000	3,700	3,000	3,600
Weighted-average common and potential dilutive shares outstanding	478,500	481,500	478,500	482,300
Earnings per share attributable to Zoetis stockholders—basic (in dollars per share)	$ 1.01	$ 0.91	$ 2.69	$ 2.33
Earnings per share attributable to Zoetis stockholders—diluted (in dollars per share)	$ 1.00	$ 0.90	$ 2.67	$ 2.31
Antidilutive securities excluded from computation of earnings per share, amount	0		0