Collaborative and Other Relationships Collaborative and Other Relationships - Equity Method Investments (Details)	3 Months Ended		6 Months Ended		1 Months Ended		3 Months Ended		6 Months Ended			12 Months Ended
	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Feb. 29, 2012 Samsung Biosimilar Agreement [Member] USD ($)	Feb. 29, 2012 Samsung Biosimilar Agreement [Member] KRW	Jun. 30, 2013 Samsung Biosimilar Agreement [Member] USD ($)	Jun. 30, 2012 Samsung Biosimilar Agreement [Member] USD ($)	Jun. 30, 2013 Samsung Biosimilar Agreement [Member] USD ($)	Jun. 30, 2013 Samsung Biosimilar Agreement [Member] KRW	Jun. 30, 2012 Samsung Biosimilar Agreement [Member] USD ($)	Dec. 31, 2012 Samsung Biosimilar Agreement [Member] USD ($)	Dec. 31, 2012 Samsung Biosimilar Agreement [Member] KRW
Schedule of Equity Method Investments [Line Items]
Contribution from Samsung to develop, manufacture and market biosimilar pharmaceuticals					$ 250,000,000	280,500,000,000
Variable interest entity, qualitative or quantitative information, ownership percentage					85.00%	85.00%
Contribution from Biogen Idec to develop, manufacture and market biosimilar pharmaceuticals					45,000,000	49,500,000,000	27,600,000		27,600,000	31,700,000,000		27,800,000	29,700,000,000
Percentage of stake in entity minimum					15.00%	15.00%
Percentage of stake in entity maximum					49.90%	49.90%
Cash contributions to Samsung Bioepis									38,600,000	43,000,000,000		32,100,000	36,000,000,000
Remaining obligation of financing arrangements							5,700,000		5,700,000	6,500,000,000
Recognized loss	(2,289,000)	(511,000)	(6,100,000)	(511,000)			(2,300,000)		(6,100,000)		(500,000)
Revenue related to technical development and technology transfer services	$ 48,770,000	$ 59,521,000	$ 103,481,000	$ 91,495,000			$ 7,400,000	$ 4,600,000	$ 14,200,000		$ 5,600,000