Subsequent Events - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended					1 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")	Dec. 31, 2012 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")	Jan. 31, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") Subsequent Event	Dec. 31, 2013 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")	Jan. 31, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") Subsequent Event	Jan. 31, 2014 Upfront Payment Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") Subsequent Event	Jan. 31, 2014 Upfront Payment Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") Subsequent Event	Jan. 31, 2014 Milestone Payment Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") Subsequent Event	Jan. 31, 2014 Milestone Payment Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") Subsequent Event
Subsequent Event [Line Items]
Consideration on agreement	$ 2,056	$ 2,766	$ 2,601	$ 3,108	$ 1,958	$ 738	$ 66,865	$ 2,481	$ 10,531	$ 72,042	$ 78,029	$ 4,042	$ 1,958	$ 25,000	$ 3,876	$ 25,000	$ 13,000	$ 10,000	$ 12,000	$ 15,000