Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current portion:
Deferred revenue, current portion	$ 320,138	$ 231,664
Deferred revenue - other, current portion	142,392	116,397
Long-term portion:
Deferred revenue, long-term portion	629,199	830,772
Deferred revenue - other	249,263	327,298
Received or receivable from Sanofi
Current portion:
Deferred revenue, current portion	177,746	115,267
Long-term portion:
Deferred revenue, long-term portion	379,936	503,474
Received or receivable from Bayer HealthCare
Current portion:
Deferred revenue, current portion	39,000	31,084
Long-term portion:
Deferred revenue, long-term portion	29,734	77,028
Mitsubishi Tanabe Pharma Corporation (MTPC) [Member]
Current portion:
Deferred revenue, current portion	14,027	9,188
Long-term portion:
Deferred revenue, long-term portion	56,106	45,940
Teva Pharmaceuticals [Member]
Current portion:
Deferred revenue, current portion	43,535	43,122
Long-term portion:
Deferred revenue, long-term portion	153,823	194,050
Received for technology license agreement
Current portion:
Deferred revenue, current portion	10,280	23,572
Long-term portion:
Deferred revenue, long-term portion	0	10,280
Other
Current portion:
Deferred revenue, current portion	35,550	9,431
Long-term portion:
Deferred revenue, long-term portion	$ 9,600	$ 0