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	799						800		(1)
Other comprehensive income	(130)							(130)
Consolidation of noncontrolling interests	6								6
Treasury stock acquired, shares				(1,800,000)	(1,300,000)
Share-based compensation awards	43			$ 47		(15)	11
Treasury stock acquired	(250)			(250)
Employee benefit plan contribution from Pfizer Inc.	1					1
Dividends declared	(190)						(190)
Ending balance (in shares) at Jun. 30, 2020			501,900,000
Ending balance at Jun. 30, 2020	2,987			$ (2,245)		1,030	5,048	(856)	5
Treasury stock, ending balance (in shares) at Jun. 30, 2020				26,900,000
Beginning balance (in shares) at Mar. 31, 2020			501,900,000
Beginning balance at Mar. 31, 2020	2,753		$ 5	$ (2,252)		1,017	4,764	(781)	0
Treasury stock, beginning balance (in shares) at Mar. 31, 2020				27,000,000.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	376						377		(1)
Other comprehensive income	(75)							(75)
Consolidation of noncontrolling interests	6								6
Treasury stock acquired, shares					(100,000)
Share-based compensation awards	22	[1]		$ 7		13	2
Dividends declared	(95)						(95)
Ending balance (in shares) at Jun. 30, 2020			501,900,000
Ending balance at Jun. 30, 2020	$ 2,987			$ (2,245)		1,030	5,048	(856)	5
Treasury stock, ending balance (in shares) at Jun. 30, 2020				26,900,000
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	$ 1,069						1,071		(2)
Other comprehensive income	107							107
Treasury stock acquired, shares				(2,100,000)	(1,000,000.0)
Share-based compensation awards	(13)			$ 9		(22)
Treasury stock acquired	(347)			(347)
Employee benefit plan contribution from Pfizer Inc.	1					1
Dividends declared	$ (238)						(238)
Ending balance (in shares) at Jun. 30, 2021	501,891,243		501,900,000
Ending balance at Jun. 30, 2021	$ 4,352		$ 5	$ (2,568)		1,044	6,492	(623)	2
Treasury stock, ending balance (in shares) at Jun. 30, 2021	27,680,413			27,700,000
Beginning balance (in shares) at Mar. 31, 2021			501,900,000
Beginning balance at Mar. 31, 2021	$ 4,092		$ 5	$ (2,412)		1,030	6,099	(633)	3
Treasury stock, beginning balance (in shares) at Mar. 31, 2021				26,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	511						512		(1)
Other comprehensive income	10							10
Treasury stock acquired, shares				(1,000,000.0)	(200,000)
Share-based compensation awards	24			$ 10		14
Treasury stock acquired	(166)			(166)
Dividends declared	$ (119)						(119)
Ending balance (in shares) at Jun. 30, 2021	501,891,243		501,900,000
Ending balance at Jun. 30, 2021	$ 4,352		$ 5	$ (2,568)		$ 1,044	$ 6,492	$ (623)	$ 2
Treasury stock, ending balance (in shares) at Jun. 30, 2021	27,680,413			27,700,000

[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.