Quarterly report pursuant to Section 13 or 15(d)

License, Clinical Trial and Sponsored Research Agreements (Other - Sponsored Research and Clinical Trial Agreements) (Narrative) (Details)

v3.21.2
License, Clinical Trial and Sponsored Research Agreements (Other - Sponsored Research and Clinical Trial Agreements) (Narrative) (Details) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Jul. 01, 2020
Jul. 03, 2017
Jun. 30, 2021
Nov. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]                
Research and development expense         $ 10,902,000 $ 9,830,000 $ 22,520,000 $ 19,144,000
Sponsored Research and Clinical Trial Agreements [Member]                
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]                
Research and development expense         1,260,000 2,816,000 3,102,000 4,166,000
Fred Hutchinson Cancer Research Center [Member] | Sponsored Research and Clinical Trial Agreements [Member] | CD20 Product or Process [Member]                
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]                
Milestones payable   $ 5,300,000            
Additional milestone payments       $ 800,000        
Research and development expense         327,000 189,000 998,000 716,000
St. Jude Children's Research Hospital [Member] | Sponsored Research and Clinical Trial Agreements [Member] | ST. Jude - XSCID [Member]                
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]                
Upfront fees paid $ 1,100,000              
Research and development expense         176,000 1,558,000 280,000 1,558,000
Mayo Clinic [Member] | Sponsored Research and Clinical Trial Agreements [Member]                
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]                
Milestones payable     $ 2,100,000          
Research and development expense         $ 233,000 $ 0 $ 233,000 $ 0
Agreement term     2 years