Deferred Revenue (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current portion:
Deferred revenue, current portion	$ 47,000	$ 50,831
Long-term portion:
Deferred revenue, long-term portion	184,199	208,342
Received or receivable from Sanofi
Current portion:
Deferred revenue, current portion	12,815	17,022
Long-term portion:
Deferred revenue, long-term portion	76,522	76,520
Received or receivable from Bayer HealthCare
Current portion:
Deferred revenue, current portion	9,738	9,212
Long-term portion:
Deferred revenue, long-term portion	26,683	27,256
Received for technology license agreement
Current portion:
Deferred revenue, current portion	23,572	23,572
Long-term portion:
Deferred revenue, long-term portion	80,994	104,566
Other
Current portion:
Deferred revenue, current portion	$ 875	$ 1,025