License and Development Agreements - Endo License and Development Agreement - Additional Information (Detail)		1 Months Ended		3 Months Ended		9 Months Ended
	Oct. 26, 2015 USD ($)	Feb. 28, 2015 USD ($)	May. 31, 2012 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Milestone Clinical_Trials	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	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
Contract revenues					$ 513,000	$ 11,759,000	$ 22,472,000
Term of Endo Agreement						10 years
Total rate of reimbursable contractor costs borne						50.00%
Deferred revenue recognized during the period				6,000,000		$ 6,000,000
Deferred revenue from research and development activities				55,000	1,298,000	909,000	12,067,000
Subsequent Event [Member]
Revenue Recognition, Milestone Method [Line Items]
Potential milestone payment receivable upon regulatory approval	$ 50,000,000
Endo Agreement [Member]
Revenue Recognition, Milestone Method [Line Items]
Contract revenues				0	500,000	$ 400,000	2,300,000
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				60,000	$ 1,300,000	$ 900,000	$ 12,100,000
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