Endo License and Development Agreement - Additional Information (Detail) (USD $)	12 Months Ended							1 Months Ended
	Dec. 31, 2013 Milestone	Dec. 31, 2012	Dec. 31, 2011	May 31, 2012	Jan. 17, 2012	Feb. 28, 2014 Subsequent Event [Member]	Jan. 23, 2014 Subsequent Event [Member]	May 31, 2012 Endo License and Development Agreement [Member]
Revenue Recognition, Milestone Method [Line Items]
Non-refundable payment received					$ 30,000,000
Potential milestone payments	95,000,000
Number of potential milestone payments	6
Potential milestone payments on intellectual property rights	35,000,000
Potential milestone payments on issuance of patent	15,000,000			15,000,000
Potential milestone payment receivable clinical development	20,000,000
Potential milestone payment receivable regulatory events	40,000,000
Payment receivable on achievement of potential sales milestones	55,000,000
Number of potential sales milestones	4
Recognized up-front payment allocated to the license	15,600,000
Recognized up-front payment to clinical trial material and development services	14,400,000
Upfront payment	0
Aggregate milestones and services revenue recognized	6,799,838	53,446,309	318,800					15,000,000
Estimated amount recognized against clinical services deliverable	6,300,000	5,200,000
Deferred revenue income of the research and development activities	2,900,000
Term of Endo Agreement	10 years
Extended patent on drug delivery technology	2020 to 2027
Milestone payment regarding licensing agreement						$ 10,000,000	$ 10,000,000