License and Development Agreements - Endo License and Development Agreement - Additional Information (Detail)		1 Months Ended				3 Months Ended
	Oct. 26, 2015 USD ($)	Nov. 30, 2015 USD ($)	Oct. 31, 2015 USD ($)	Feb. 28, 2015 USD ($)	May. 31, 2012 USD ($)	Mar. 31, 2016 USD ($) Milestone Clinical_Trials	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	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		$ 50,000,000
Milestone payment upon regulatory approval deferred for future revenue recognition		$ 20,000,000
Patent extension starting period						2020
Patent extension ending period						2027
Deferred revenue refund payment						$ 2,900,000
Royalty payment description						$50 million upon regulatory approval, earned in October 2015 and received in November 2015, with the revenue recognition treatment for $20 million of such $50 million payment deferred due to the fact that all or a portion of such $20 million is contingently refundable to Endo based on a third party generic introduction in the U.S. during the patent extension period from 2020 to 2027. Should such introduction occur any time during the 2020 to 2027 period, a refund would be due to Endo based on the number of complete calendar months beyond December 31, 2019 where the first generic was sold over the denominator of 84 months multiplied by $20 million. For example, if a generic product were to be introduced in the U.S. in January of 2026, that would mean that 72 of the 84 months of patent exclusivity would have been earned and 12 months would have to be refunded. The calculation would be 12/84, multiplied by $20 million, for a refund of $2.9 million. The method of the refund payment to Endo would be made first by crediting against milestone payments owed to the Company, second by reducing the royalty by 50% until the $2.9 million is paid back, and third by the Company making a payment in the amount due to Endo. Otherwise, the $20 million will be earned as revenue each month over the patent extension period from 2020 to 2027;
Royalty reduction percentage						50.00%
Payment receivable on achievement of potential sales milestones						$ 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
Contract revenues							$ 11,408,000
Term of Endo Agreement						10 years
Total rate of reimbursable contractor costs borne						50.00%
Deferred revenue from research and development activities						$ 4,000	775,000
Deferred revenue recognized during the period								$ 6,000,000
Endo Agreement [Member]
Revenue Recognition, Milestone Method [Line Items]
Contract revenues						400,000
Deferred revenue related to upfront license fee						$ 0
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						$ 4,000	$ 800,000
Clinical Trials Full Enrollment [Member]
Revenue Recognition, Milestone Method [Line Items]
Potential milestone payment received, clinical development						$ 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