License and Collaboration Agreements - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		0 Months Ended	6 Months Ended		0 Months Ended	3 Months Ended		6 Months Ended		0 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Nov. 10, 2009 Sanofi [Member]	Jun. 30, 2014 Sanofi [Member]	Jun. 30, 2014 Sanofi [Member] License and Collaboration Agreements [Member]	May 05, 2011 PharmaEngine [Member]	Jun. 30, 2014 PharmaEngine [Member] License and Collaboration Agreements [Member]	Jun. 30, 2013 PharmaEngine [Member] License and Collaboration Agreements [Member]	Jun. 30, 2014 PharmaEngine [Member] License and Collaboration Agreements [Member]	Jun. 30, 2013 PharmaEngine [Member] License and Collaboration Agreements [Member]	May 05, 2011 PharmaEngine [Member] Development and Regulatory Milestone [Member]	May 05, 2011 PharmaEngine [Member] Sales Milestone [Member]	Mar. 31, 2012 PharmaEngine [Member] Phase 3 Clinical Trial in Pancreatic Cancer [Member]	Jun. 30, 2014 Actavis [Member]	Dec. 31, 2013 Actavis [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront license fee received					$ 60,000,000
Milestone license fee received						25,000,000										2,700,000
Agreement termination scheduled date			Dec. 17, 2014
Expected development period from the effective date of agreement					12 years
Development services performed							5,800,000
Upfront license fees paid								10,000,000
Maximum milestone payment obligation													80,000,000	130,000,000
Milestone payment															5,000,000
Research and development expenses	33,795,000	42,465,000	64,119,000	79,454,000					100,000	200,000	200,000	500,000
Eligible milestone payments																15,500,000
Agreement expiration term respect to each product																10 years
Additional renewal term																2 years
Notice period of termination																90 days
Milestones and development expenses																$ 3,000,000	$ 2,100,000