Segment and Other Revenue Information (Revenue by Animal Species) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jul. 01, 2012	Apr. 01, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenue from External Customer [Line Items]
Revenue	$ 1,254,000,000	$ 1,103,000,000	$ 1,114,000,000	$ 1,090,000,000	$ 1,176,000,000	$ 1,019,000,000	$ 1,094,000,000	$ 1,047,000,000	$ 4,561,000,000	[1]	$ 4,336,000,000	[1]	$ 4,233,000,000	[1],[2]
Livestock [Member]
Revenue from External Customer [Line Items]
Revenue									2,931,000,000		2,806,000,000		2,778,000,000
Cattle
Revenue from External Customer [Line Items]
Revenue									1,631,000,000		1,608,000,000		1,617,000,000
Swine
Revenue from External Customer [Line Items]
Revenue									655,000,000		590,000,000		562,000,000
Poultry
Revenue from External Customer [Line Items]
Revenue									541,000,000		501,000,000		501,000,000
Other (Fish and Sheep)
Revenue from External Customer [Line Items]
Revenue									104,000,000		107,000,000		98,000,000
Companion Animal [Member]
Revenue from External Customer [Line Items]
Revenue									1,630,000,000		1,530,000,000		1,455,000,000
Horses
Revenue from External Customer [Line Items]
Revenue									179,000,000		187,000,000		168,000,000
Dogs and Cats
Revenue from External Customer [Line Items]
Revenue									$ 1,451,000,000		$ 1,343,000,000		$ 1,287,000,000

[1] Revenue denominated in euros were $693 million in 2013, $639 million in 2012, and $710 million in 2011.

[2] Includes revenue and expenses from acquisitions from the acquisition date, see Note 3. Basis of Presentation and Note 5. Acquisitions, Divestitures and Certain Investments.