Annual report pursuant to Section 13 and 15(d)

Basis of Presentation and Significant Accounting Policies - Additional Information (Details)

v3.3.1.900
Basis of Presentation and Significant Accounting Policies - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Contract Revenues [Abstract]      
Decrease in Previously Invoiced Balances from NIAID   $ 1,800,000  
Research and Development Expense [Abstract]      
Adjustment to the Company's accrued estimates for clinical trial activities from inception of the trials   200,000  
Impairment loss recognized $ 0 $ 0 $ 0
Unrecognized tax benefits, income tax penalties or interest charged $ 0    
Equipment [Member] | Minimum [Member]      
Basis Of Presentation And Significant Accounting Policies [Line Items]      
Useful lives 3 years    
Equipment [Member] | Maximum [Member]      
Basis Of Presentation And Significant Accounting Policies [Line Items]      
Useful lives 7 years    
Leasehold Improvements, Buildings and Building Improvements [Member] | Minimum [Member]      
Basis Of Presentation And Significant Accounting Policies [Line Items]      
Useful lives 1 year    
Leasehold Improvements, Buildings and Building Improvements [Member] | Maximum [Member]      
Basis Of Presentation And Significant Accounting Policies [Line Items]      
Useful lives 15 years