CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions		Total	Common Stock	[1]	Treasury Stock	[1]	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Equity Attributable to Noncontrolling Interests	Share Repurchase Program
Treasury shares		15,800,000
Common stock, shares outstanding		501,900,000
Beginning balance at Dec. 31, 2017		$ 1,786	$ 5		$ (852)		$ 1,013	$ 2,109	$ (505)	$ 16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss)		1,424						1,428		(4)
Other comprehensive loss		$ (124)							(124)	0
Stock-based compensation		0
Treasury Stock, Shares, Acquired		1,700,000									8,200,000
The fair value of our noncontrolling interest in a VIE		$ 26								12
Share-based compensation awards	[2]	$ 81			63		24	(6)
Share repurchase program		0
Treasury stock acquired	[3]	$ (698)			(698)
Employee benefit plan contribution from Pfizer Inc.	[4]	3					3
Dividends declared		(261)						(261)
Ending balance at Dec. 31, 2018		$ 2,185	5		(1,487)		1,026	3,270	(629)
Treasury shares		22,300,000
Common stock, shares outstanding		501,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss)		$ 1,500						1,500		0
Other comprehensive loss		$ (97)							(97)	0
Stock-based compensation		0
Treasury Stock, Shares, Acquired		1,800,000									5,800,000
Share-based compensation awards	[2]	$ 73			71		15	(13)
Share repurchase program		0
Treasury stock acquired	[3]	$ (626)			(626)
Employee benefit plan contribution from Pfizer Inc.	[4]	3					3
Dividends declared		(330)						(330)
Ending balance at Dec. 31, 2019		$ 2,708	5		(2,042)		1,044	4,427	(726)	0
Treasury shares		26,363,022
Common stock, shares outstanding		501,891,243
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss)		$ 1,636								(2)
Other comprehensive loss		$ (4)							(4)	0
Treasury Stock, Shares, Acquired		1,600,000									1,800,000
Consolidation of a noncontrolling interest	[4]	$ 6								6
Share-based compensation awards	[2]	78			62		18	(2)
Treasury stock acquired	[3]	(250)			(250)
Employee benefit plan contribution from Pfizer Inc.	[4]	3					3
Dividends declared		(404)						(404)
Ending balance at Dec. 31, 2020		$ 3,773	$ 5		$ (2,230)		$ 1,065	$ 5,659	$ (730)	$ 4
Treasury shares		26,573,492
Common stock, shares outstanding		501,891,243

[1] For the twelve months ended December 31, 2018, represents the acquisition of a European livestock monitoring company.

[2] Includes the issuance of shares of Zoetis Inc. common stock and the reacquisition of shares of treasury stock associated with exercises of employee share-based awards. Also includes the reacquisition of shares of treasury stock associated with the vesting of employee share-based awards to satisfy tax withholding requirements. For additional information, see Note 15. Share-based Payments and Note 16. Stockholders' Equity.

[3] Reflects the acquisition of treasury shares in connection with the share repurchase program. For additional information, see Note 16. Stockholders' Equity.

[4] Represents contributed capital from Pfizer Inc. associated with service credit continuation for certain Zoetis Inc. employees in Pfizer Inc.'s U.S. qualified defined benefit and U.S. retiree medical plans. See Note 14. Benefit Plans.