Annual report pursuant to Section 13 and 15(d)

Milestones and Sponsored Research Agreements - Additional Information (Detail)

v3.6.0.2
Milestones and Sponsored Research Agreements - Additional Information (Detail) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Aug. 31, 2016
Mar. 31, 2016
Feb. 29, 2016
Dec. 31, 2016
Dec. 31, 2015
Oct. 31, 2016
Mar. 31, 2015
Research And Development Expense       $ (35,134) $ (29,810)    
Payments to Acquire in Process Research and Development       200      
Checkpoint Therapeutics, Inc [Member]              
Stock Issued During Period, Value, Purchase of Assets       22,000      
Helocyte Inc [Member]              
Payments For Research And Development Expenses $ 2,000     4,400      
Helocyte Inc [Member] | Pep Vax [Member]              
Payments For Research And Development Expenses 1,000     2,000      
Helocyte Inc [Member] | Triplex [Member]              
Payments For Research And Development Expenses $ 1,000     2,400      
Mustang Bio, Inc [Member]              
Research And Development Expense Payable Milestone Payment       2,000 $ 1,500   $ 2,000
UCLB [Member]              
Payment of Upfront Fees       $ 100      
Milestone Payments   $ 400          
UCLB [Member] | Minimum [Member]              
Royalty Percentage       3.00%      
UCLB [Member] | Maximum [Member]              
Royalty Percentage       5.00%      
Cellvation [Member]              
Research And Development Expense Payable Milestone Payment           $ 700  
Research And Development Expense       $ 200      
City Of Hope [Member]              
Research And Development Expense Payable Milestone Payment   2,000 $ 3,400        
Payments to Acquire in Process Research and Development   $ 1,000 $ 1,000