License and Development Agreements - Endo License and Development Agreement - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Milestone Clinical_Trials	Jun. 30, 2014 USD ($)	Jan. 31, 2014 USD ($)	Jan. 31, 2012 USD ($)
Revenue Recognition, Milestone Method [Line Items]
Non-refundable payment received						$ 30,000,000
Potential milestone payments on intellectual property rights			$ 15,000,000
Potential payments upon filing and acceptance			10,000,000
Potential milestone payment receivable upon regulatory approval			50,000,000
Payment receivable on achievement of potential sales milestones	$ 55,000,000		$ 55,000,000
Number of potential sales milestones | Milestone			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			30,000,000
Recognition of deferred revenue	0		400,000
Contract revenue	351,000	$ 10,675,000	$ 11,759,000	$ 21,959,000
Term of Endo Agreement			10 years
Total rate of reimbursable contractor costs borne			50.00%
Deferred revenue recognized during the period	80,000	2,318,000	$ 855,000	10,770,000
Clinical Trials Full Enrollment [Member]
Revenue Recognition, Milestone Method [Line Items]
Potential milestone payment received, clinical development	20,000,000		$ 20,000,000
Number of clinical trials | Clinical_Trials			2
Clinical Trials One [Member]
Revenue Recognition, Milestone Method [Line Items]
Potential milestone payment received, clinical development					$ 10,000,000
Clinical Trials Two [Member]
Revenue Recognition, Milestone Method [Line Items]
Potential milestone payment received, clinical development		10,000,000		10,000,000
Endo Agreement [Member]
Revenue Recognition, Milestone Method [Line Items]
Total rate of reimbursable contractor costs borne			50.00%
Reimbursement rate of costs by Endo to the company as per agreement			100.00%
Percentage of credit against potential future milestones			50.00%
Deferred revenue from research and development activities	$ 900,000	$ 10,800,000	$ 900,000	$ 10,800,000