Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 1,674	$ 1,584	$ 1,547	$ 1,455	$ 1,564	$ 1,480	$ 1,415	$ 1,366	$ 6,260		$ 5,825		$ 5,307
Costs and expenses	1,219	1,050	1,070	1,069	1,132	1,015	973	947
Restructuring charges and certain acquisition-related costs	18	6	22	5	14	47	5	2	51		68		19
Income before provision for taxes on income	437	528	455	381	418	418	437	417	1,801	[1]	1,690	[1]	1,525	[1]
Provision for taxes on income	53	95	84	69	73	71	55	67	301	[2],[3]	266	[2],[3]	663	[2],[3]
Net income before allocation to noncontrolling interests	384	433	371	312	345	347	382	350	1,500		1,424		862
Less: net loss attributable to noncontrolling interests	0	0	0	0	0	0	(2)	(2)	0		(4)		(2)
Net income attributable to Zoetis	$ 384	$ 433	$ 371	$ 312	$ 345	$ 347	$ 384	$ 352	$ 1,500		$ 1,428		$ 864
Earnings per common share--basic	$ 0.81	$ 0.91	$ 0.77	$ 0.65	$ 0.72	$ 0.72	$ 0.79	$ 0.72	$ 3.14		$ 2.96		$ 1.76
Earnings per common share--diluted	$ 0.80	$ 0.90	$ 0.77	$ 0.65	$ 0.71	$ 0.71	$ 0.79	$ 0.72	$ 3.11		$ 2.93		$ 1.75

[1] Defined as income before provision for taxes on income.

[2] In 2017, the Provision for taxes on income reflects the following: • the change in the jurisdictional mix of earnings, which includes the impact of the location of earnings from (i) operations and (ii) restructuring charges related to the operational efficiency initiative and supply network strategy, as well as repatriation costs. The jurisdictional mix of earnings can vary as a result of repatriation decisions and as a result of operating fluctuations in the normal course of business, the impact of non-deductible items and the extent and location of other income and expense items, such as restructuring charges/(benefits), asset impairments and gains and losses on asset divestitures; • a $212 million net discrete provisional tax expense recorded in the fourth quarter of 2017, related to the impact of the Tax Act enacted on December 22, 2017, including a one-time mandatory deemed repatriation tax, partially offset by a net tax benefit related to the remeasurement of the deferred tax assets and liabilities, as of the date of enactment, due to the reduction in the U.S. federal corporate tax rate; • U.S. tax benefit related to U.S. Research and Development Tax Credit and the U.S. Domestic Production Activities deduction; • a $15 million discrete tax benefit recorded in the fourth quarter of 2017 related to the effective settlement of certain issues with U.S. and non-U.S. tax authorities; • a $9 million discrete tax benefit recorded in 2017 related to the excess tax benefits for share-based compensation payments; • a $3 million discrete tax benefit recorded in the first quarter of 2017 related to a remeasurement of the company’s deferred tax assets and liabilities using the tax rates expected to be in place going forward; • tax expense related to the changes in valuation allowances and the resolution of other tax items; and • tax expense related to changes in uncertain tax positions (see D. Tax Contingencies).

[3] In 2019, the Provision for taxes on income reflects the following: • the change in the jurisdictional mix of earnings, which includes the impact of the location of earnings from operations and repatriation costs. The jurisdictional mix of earnings can vary as a result of repatriation decisions, operating fluctuations in the normal course of business, the impact of non-deductible items, and the extent and location of other income and expense items, such as gains and losses on asset divestitures; • the impact of the GILTI tax, a new provision of the Tax Act, which became effective for the company in the first quarter of 2019; • a $20 million discrete tax benefit recorded in 2019 related to the excess tax benefits for share-based compensation payments; • an $18 million discrete tax benefit related to the changes in valuation allowances; • a $14 million net discrete tax benefit recorded in the third quarter of 2019, due to a change in tax basis related to purchase accounting; • a $12 million net discrete tax benefit recorded in 2019, related to changes in various other tax items; • an $8 million discrete tax benefit recorded in 2019 related to a remeasurement of deferred tax assets and liabilities as a result of a change in U.S. and non-U.S. statutory tax rates; • U.S. tax benefit related to U.S. Research and Development Tax Credit; and • tax expense related to changes in uncertain tax positions (see D. Tax Contingencies). ^(b)   In 2018, the Provision for taxes on income reflects the following: • the change in the jurisdictional mix of earnings, which includes the impact of the location of earnings from operations and repatriation costs. The jurisdictional mix of earnings can vary as a result of repatriation decisions, operating fluctuations in the normal course of business, the impact of non-deductible items, and the extent and location of other income and expense items, such as gains and losses on asset divestitures; • the reduction of the U.S. federal corporate income tax rate, from 35% to 21%, effective January 1, 2018, pursuant to the Tax Act; • a $45 million net tax benefit recorded in 2018, associated with a measurement-period adjustment to the one-time mandatory deemed repatriation tax on the company’s undistributed non-U.S. earnings pursuant to the Tax Act; • a $23 million discrete tax benefit recorded in 2018 related to the favorable impact of certain tax accounting method changes; • a $15 million discrete tax benefit recorded in 2018 related to the excess tax benefits for share-based compensation payments; • a $5 million discrete tax benefit recorded in 2018 related to a remeasurement of deferred tax assets and liabilities as a result of a change in non-U.S. statutory tax rates; • U.S. tax benefit related to U.S. Research and Development Tax Credit; • tax expense related to the changes in valuation allowances and the resolution of other tax items; and • tax expense related to changes in uncertain tax positions (see D. Tax Contingencies).