| 
           License Agreements - Additional Information (Detail) 
         | 
        1 Months Ended | 12 Months Ended | 1 Months Ended | 3 Months Ended | 12 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 
           Feb. 22, 2013
 
          USD ($) 
         | 
        
           Feb. 22, 2013
 
          EUR (€) 
         | 
        
           Dec. 31, 2014
 
          USD ($) 
         | 
        
           Dec. 31, 2013
 
          USD ($) 
         | 
        
           Dec. 31, 2012
 
          USD ($) 
         | 
        
           Dec. 31, 2014
 
          Falk [Member]
 
          USD ($) 
         | 
        
           Dec. 31, 2014
 
          Falk [Member]
 
          EUR (€) 
         | 
        
           Nov. 30, 2007
 
          UCLB [Member]
 
          USD ($) 
         | 
        
           Mar. 31, 2012
 
          UCLB [Member]
 
          USD ($) 
         | 
        
           Dec. 31, 2014
 
          UCLB [Member] 
         | 
        
           Dec. 31, 2014
 
          UCLB [Member]
 
          Minimum [Member] 
         | 
        
           Dec. 31, 2014
 
          UCLB [Member]
 
          Maximum [Member] 
         | 
        
           Dec. 31, 2014
 
          Ovamed [Member]
 
          USD ($) 
         | 
        
           Dec. 31, 2012
 
          Ovamed [Member]
 
          USD ($) 
         | 
        
           Dec. 31, 2011
 
          Ovamed [Member]
 
          USD ($) 
         | 
        
           Feb. 22, 2013
 
          FU Berlin [Member]
 
          USD ($) 
         | 
        
           Feb. 22, 2013
 
          FU Berlin [Member]
 
          EUR (€) 
         | 
        
           Dec. 31, 2014
 
          FU Berlin [Member]
 
          USD ($) 
         | 
        
           Dec. 31, 2013
 
          FU Berlin [Member]
 
          USD ($) 
         | 
        
           Feb. 22, 2013
 
          FU Berlin [Member]
 
          Joint Ownership and Exclusive License Agreement [Member]
 
          EUR (€) 
         | 
        
           Feb. 22, 2013
 
          FU Berlin [Member]
 
          Minimum [Member]
 
          Joint Ownership and Exclusive License Agreement [Member] 
         | 
        
           Feb. 22, 2013
 
          FU Berlin [Member]
 
          Maximum [Member]
 
          Joint Ownership and Exclusive License Agreement [Member] 
         | 
      |
| Business Acquisition [Line Items] | ||||||||||||||||||||||
| Contingent milestone payments to OvaMed | $ 5,450,000 | |||||||||||||||||||||
| Milestone payments to related party | 1,200,000 | 1,000,000 | 1,500,000 | |||||||||||||||||||
| Cash paid to Falk | 6,100,000 | 5,000,000 | ||||||||||||||||||||
| Royalty payable to Falk | 1.00% | 1.00% | ||||||||||||||||||||
| Additional payments to Falk | 1,800,000 | 1,500,000 | ||||||||||||||||||||
| Remaining amount payable to Falk | 3,000,000 | 2,500,000 | ||||||||||||||||||||
| Percentage responsibility for clinical testing | 50.00% | 50.00% | 50.00% | |||||||||||||||||||
| Total amount paid for purchase of manufacturing agreement | 1,500,000 | |||||||||||||||||||||
| Related Party Transaction Equal Installment Amount | 500,000 | |||||||||||||||||||||
| Property Lease Period | 5 years | 1 year | ||||||||||||||||||||
| Upfront payment for license | 100,000 | |||||||||||||||||||||
| Future milestone payment | 22,000,000 | |||||||||||||||||||||
| Recognition of milestone payment | 250,000 | |||||||||||||||||||||
| Royalty Percentage | 3.00% | 5.00% | ||||||||||||||||||||
| Agreement termination notice period | 30 days | |||||||||||||||||||||
| Management fee right to reduce transfer fee component agreed days | 10 days | |||||||||||||||||||||
| Management fee right to reduce transfer fee component additional amount agreed days | 90 days | |||||||||||||||||||||
| Potential Net Sales Of Products Ranging Minimum | 1.00% | 1.00% | 1.00% | |||||||||||||||||||
| Potential Net Sales Of Products Ranging Maximum | 2.50% | 2.50% | 2.50% | |||||||||||||||||||
| Research and development expense | 10,239,000 | 25,682,000 | 17,468,000 | 788,000 | 648,000 | 4,655,000 | 3,830,000 | |||||||||||||||
| Letter Agreement Description | The Letter Agreement provides that Ovamed will retain a 10% interest in FU Berlins rights to the Joint Intellectual Property in the Ovamed Territory. | The Letter Agreement provides that Ovamed will retain a 10% interest in FU Berlins rights to the Joint Intellectual Property in the Ovamed Territory. | The Letter Agreement provides that Ovamed will retain a 10% interest in FU Berlins rights to the Joint Intellectual Property in the Ovamed Territory. | The Letter Agreement provides that Ovamed will retain a 10% interest in FU Berlins rights to the Joint Intellectual Property in the Ovamed Territory. | ||||||||||||||||||
| Termination Fee | 167,000 | 183,000 | ||||||||||||||||||||
| Research and Development Expense Maximum Paid Amount | $ 1,246,000 | € 1,025,000 | ||||||||||||||||||||