Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator
Net income before allocation to noncontrolling interests	$ 312	$ 350
Less: Net loss attributable to noncontrolling interests	0	(2)
Net income attributable to Zoetis Inc.	$ 312	$ 352
Denominator
Weighted-average common shares outstanding	479.6	485.9
Common stock equivalents: stock options, RSUs, PSUs and DSUs	3.5	3.9
Weighted-average common and potential dilutive shares outstanding	483.1	489.8
Earnings per share attributable to Zoetis stockholders—basic (in dollars per share)	$ 0.65	$ 0.72
Earnings per share attributable to Zoetis stockholders—diluted (in dollars per share)	$ 0.65	$ 0.72
Stock options
Denominator
Antidilutive securities excluded from computation of earnings per share, amount	1.0