CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (UNAUDITED) - USD ($) $ in Millions		Total		Common Stock	Treasury Stock	Treasury Stock Share Repurchase Program	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Equity Attributable to Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2019				501,900,000
Beginning balance at Dec. 31, 2019		$ 2,708		$ 5	$ (2,042)		$ 1,044	$ 4,427	$ (726)	$ 0
Treasury stock, beginning balance (in shares) at Dec. 31, 2019					26,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		1,278						1,279		(1)
Other comprehensive loss		(9)							(9)
Consolidation of noncontrolling interests		6								6
Treasury stock acquired, shares					(1,800,000)	(1,600,000)
Share-based compensation awards		62			$ 58		(6)	10
Treasury stock acquired		(250)			(250)
Employee benefit plan contribution from Pfizer Inc.		2					2
Dividends declared		(190)						(190)
Ending balance (in shares) at Sep. 30, 2020				501,900,000
Ending balance at Sep. 30, 2020		3,607		$ 5	$ (2,234)		1,040	5,526	(735)	5
Treasury stock, ending balance (in shares) at Sep. 30, 2020					26,600,000
Beginning balance (in shares) at Jun. 30, 2020				501,900,000
Beginning balance at Jun. 30, 2020		2,987		$ 5	$ (2,245)		1,030	5,048	(856)	5
Treasury stock, beginning balance (in shares) at Jun. 30, 2020					26,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		479						479
Other comprehensive loss		121							121
Treasury stock acquired, shares						(300,000)
Share-based compensation awards		19	[1]		$ 11		9	(1)
Employee benefit plan contribution from Pfizer Inc.	[2]	1					1
Ending balance (in shares) at Sep. 30, 2020				501,900,000
Ending balance at Sep. 30, 2020		$ 3,607		$ 5	$ (2,234)		1,040	5,526	(735)	5
Treasury stock, ending balance (in shares) at Sep. 30, 2020					26,600,000
Beginning balance (in shares) at Dec. 31, 2020		501,891,243		501,900,000
Beginning balance at Dec. 31, 2020		$ 3,773		$ 5	$ (2,230)		1,065	5,659	(730)	4
Treasury stock, beginning balance (in shares) at Dec. 31, 2020		26,573,492			26,600,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		$ 1,621						1,623		(2)
Other comprehensive loss		63							63
Treasury stock acquired, shares					(3,100,000)	(1,200,000)
Share-based compensation awards		5			$ 16		(11)
Treasury stock acquired		(545)			(545)
Employee benefit plan contribution from Pfizer Inc.		2					2
Dividends declared		$ (238)						(238)
Ending balance (in shares) at Sep. 30, 2021		501,891,243		501,900,000
Ending balance at Sep. 30, 2021		$ 4,681		$ 5	$ (2,759)		1,056	7,044	(667)	2
Treasury stock, ending balance (in shares) at Sep. 30, 2021		28,517,186			28,500,000
Beginning balance (in shares) at Jun. 30, 2021				501,900,000
Beginning balance at Jun. 30, 2021		$ 4,352		$ 5	$ (2,568)		1,044	6,492	(623)	2
Treasury stock, beginning balance (in shares) at Jun. 30, 2021					27,700,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		552						552
Other comprehensive loss		(44)							(44)
Treasury stock acquired, shares					(1,000,000.0)	(200,000)
Share-based compensation awards		18			$ 7		11
Treasury stock acquired		(198)			(198)
Employee benefit plan contribution from Pfizer Inc.		$ 1					1
Ending balance (in shares) at Sep. 30, 2021		501,891,243		501,900,000
Ending balance at Sep. 30, 2021		$ 4,681		$ 5	$ (2,759)		$ 1,056	$ 7,044	$ (667)	$ 2
Treasury stock, ending balance (in shares) at Sep. 30, 2021		28,517,186			28,500,000

[1] (b)    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 12. Share-based Payments and Note 13. Stockholders' Equity.

[2] (d)    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.