Acquisitions (Details) (USD $) In Millions	1 Months Ended	3 Months Ended			9 Months Ended
	Mar. 31, 2010	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Jul. 07, 2011 Janssen Pharmaceutica NV (J&J) [Member]	Jul. 20, 2010 Alnara Pharmaceuticals [Member]	May 28, 2010 Animal Health Sligo [Member]
Total purchase price							$ 307.8	$ 291.7
Cash paid for acquisition								188.7	148.4
Business Acquisition, Contingent Consideration, Potential Cash Payment								200.0
Business Acquisition, Contingent Consideration, at Fair Value								103.0
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets									76.2
Business Acquisition, Purchase Price Allocation, Goodwill								100.5
Business Acquisition, Purchase Price Allocation, Deferred Income Taxes Asset (Liability), Net								(92.4)
Acquired in-process research and development	50.0	0	388.0	0	388.0	50.0
Acquired Indefinite-lived Intangible Asset, Amount								$ 264.0