XML 29 R19.htm IDEA: XBRL DOCUMENT v3.20.2
Significant Accounting Policies (Narrative) (Details)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
USD ($)
ft²
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
ft²
Jun. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Certificates of deposit         $ 13,000
Reimbursement from National Institutes of Health research grants $ 1,100 $ 1,400 $ 2,400 $ 2,200  
Leases, discount rate 5.50%   5.50%    
Reduction of non-current lease liability and offsetting reduction in right-of-use assets $ 22,500 $ 22,500 $ 45,000 $ 45,000  
Austin [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Office space | ft² 6,000   6,000    
Lease expiration date     Dec. 31, 2020