License Agreements - Additional Information (Detail) - Advirna [Member] - USD ($)
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]    
Annual maintenance fee $ 100,000  
Royalty payments 1.00%  
Effective license period 90 days  
Research and Development Expenses [Member]    
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]    
One-time milestone payment   $ 350,000