Goodwill and Other Intangible Assets (Goodwill) (Details) - USD ($) $ in Millions			3 Months Ended		12 Months Ended
		Jul. 31, 2018	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning balance				$ 1,510	$ 1,510	$ 1,481
Additions / Adjustments	[1]				1,025	17
Other	[2]				(16)	12
Ending balance					2,519	1,510
Abaxis Inc
Goodwill [Roll Forward]
Purchase price allocation amount		$ 977
Manufacturing Business in Ireland [Member]
Goodwill [Roll Forward]
Purchase price allocation amount					48
Irish biologic therapeutics company
Goodwill [Roll Forward]
Additions / Adjustments			$ 9
Consolidation of a European livestock monitoring company
Goodwill [Roll Forward]
Additions / Adjustments	[1]		$ 2	10
United States
Goodwill [Roll Forward]
Beginning balance				671	671	661
Additions / Adjustments	[1]				594	10
Other	[2]				0	0
Ending balance					1,265	671
International
Goodwill [Roll Forward]
Beginning balance				$ 839	839	820
Additions / Adjustments	[1]				431	7
Other	[2]				(16)	12
Ending balance					1,254	$ 839
Agribusiness Products | International
Goodwill [Roll Forward]
Other	[2]				2
Guarulhos, Brazil | International
Goodwill [Roll Forward]
Other	[2]				$ 3

[1] For 2018, primarily includes a $977 million purchase price allocation associated with the acquisition of Abaxis and $48 million related to the acquisition of a manufacturing business in Ireland. See Note 5. Acquisitions and Divestitures. For 2017, primarily represents $9 million related to the acquisition of an Irish biologic therapeutics company in the third quarter of 2017, as well as $10 million related to the consolidation of a European livestock monitoring company, a variable interest entity of which Zoetis is the primary beneficiary, in the first quarter of 2017, partially offset by a $2 million reduction to the consolidation of a European livestock monitoring company in the third quarter of 2017.

[2] Includes adjustments for foreign currency translation. For 2018, also includes $2 million related to the divestiture of certain agribusiness products within our International segment. For 2017, also includes $3 million related to the sale of our manufacturing site in Guarulhos, Brazil.