License and Development Agreements - Endo License and Development Agreement - Additional Information (Detail)
$ in Thousands
 1 Months Ended 12 Months Ended
Oct. 26, 2015
USD ($)
Nov. 30, 2015
USD ($)
Oct. 31, 2015
USD ($)
Feb. 28, 2015
USD ($)
May. 31, 2012
USD ($)
Dec. 31, 2015
USD ($)
Milestone
Clinical_Trials
Dec. 31, 2014
USD ($)
Dec. 31, 2013
USD ($)
Jun. 30, 2014
USD ($)
Jan. 31, 2014
USD ($)
Jan. 31, 2012
USD ($)
Revenue Recognition, Milestone Method [Line Items]                      
Non-refundable payment received                     $ 30,000
Potential milestone payments on intellectual property rights         $ 15,000            
Potential payments upon filing and acceptance       $ 10,000              
Potential milestone payment receivable upon regulatory approval $ 50,000   $ 50,000                
Milestone payment upon regulatory approval deferred for future revenue recognition   $ 20,000                  
Patent extension starting period           2020          
Patent extension ending period           2027          
Deferred revenue refund payment           $ 2,900          
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          
Number of potential sales milestones | Milestone           4          
Recognized up-front payment allocated to the license           $ 15,600          
Recognized up-front payment to clinical trial material and development services           14,400          
Contract revenues           $ 41,759 $ 22,749 $ 6,800      
Term of Endo Agreement           10 years          
Total rate of reimbursable contractor costs borne           50.00%          
Deferred revenue recognized during the period           $ 6,000 6,000        
Deferred revenue from research and development activities           909 12,712 2,783      
Milestone payment receivable remaining revenue           30,000          
Endo Agreement [Member]                      
Revenue Recognition, Milestone Method [Line Items]                      
Contract revenues           $ 400 2,500 6,300      
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 $ 12,700 $ 2,800      
Clinical Trials Full Enrollment [Member]                      
Revenue Recognition, Milestone Method [Line Items]                      
Potential milestone payment received, clinical development           $ 20,000          
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  
Clinical Trials Two [Member]                      
Revenue Recognition, Milestone Method [Line Items]                      
Potential milestone payment received, clinical development                 $ 10,000