Deferred Revenue (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current portion:
Deferred revenue, current	$ 51,640	$ 54,723
Long-term portion:
Deferred revenue, noncurrent	248,610	285,856
Collaboration Agreement with Sanofi [Member]
Current portion:
Deferred revenue, current	20,011	19,506
Long-term portion:
Deferred revenue, noncurrent	86,017	97,081
Collaboration Agreement with Bayer HealthCare LLC [Member]
Current portion:
Deferred revenue, current	7,907	9,884
Long-term portion:
Deferred revenue, noncurrent	34,456	37,067
Technology License Agreements [Member]
Current portion:
Deferred revenue, current	23,572	25,008
Long-term portion:
Deferred revenue, noncurrent	128,137	151,708
Other Deferred Revenue Agreements [Member]
Current portion:
Deferred revenue, current	$ 150	$ 325