Property, Plant and Equipment (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2012
Property, Plant and Equipment
Depreciation expense	$ 164.3	$ 143.9	$ 144.9
Total cost	2,683.3	2,353.5
Hillerod Denmark Facility
Property, Plant and Equipment
Interest cost capitalization related to large-scale biologic manufacturing facility	25.4	32.6	28.6
Total cost				465.9
Average estimated useful life	20 years
Research Triangle Park Facility [Member]
Property, Plant and Equipment
Total cost	47.8
Average estimated useful life	15 years
Cambridge Leases
Property, Plant and Equipment
Construction cost incurred not yet paid	86.5	2.2
Eisai [Member]
Property, Plant and Equipment
Term Of Lease	10 years
Cancellation Period of Lease	5 years
Minimum [Member] | Cambridge Leases
Property, Plant and Equipment
Expected charges to vacate building	15.0
Maximum [Member] | Cambridge Leases
Property, Plant and Equipment
Expected charges to vacate building	$ 30.0