Endo License and Development Agreement - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended		1 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Milestone	Jun. 30, 2012	Dec. 31, 2012	Jan. 17, 2012	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		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		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	1,908,949	16,297,972	3,530,926	32,802,137			15,000,000
Estimated amount recognized against clinical services deliverable			3,400,000		5,200,000
Deferred revenue income of the research and development activities	$ 5,900,000		$ 5,900,000
Term of Endo Agreement			10 years
Extended patent on drug delivery technology			2020 to 2027