License and Collaboration Agreements - License, Collaboration and Other Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	$ 6,132	$ 16,846	$ 24,190	$ 29,675
Baxter Healthcare [Member] | Hemophilia [Member]
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	741	3,556	5,794	4,486
Roche [Member] | PEGASYS and MIRCERA [Member]
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	2,011	1,283	5,134	3,849
Amgen Inc [Member] | Neulasta [Member]
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	1,250	1,250	3,750	3,750
Affymax Inc [Member] | Omontys [Member]
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	198	2,440	2,610	3,343
Bayer Healthcare LLC [Member] | BAY41-6551 (Amikacin Inhale) [Member]
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	714	750	2,257	2,250
Other [Member]
License And Collaboration Agreements [Line Items]
License, collaboration, and other revenue	$ 1,218	$ 7,567	$ 4,645	$ 11,997