XML 85 R28.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Significant Accounting Policies (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Jan. 01, 2019
Significant Accounting Policies      
Minimum period for maturity dates for short-term investments 90 days 90 days  
Accumulated deficit $ (445,070) $ (435,684)  
Lease accounting      
Operating lease liabilities 89    
Right of use operating assets $ 89    
Discount rate used for discounting future payments 13.60%    
Current operating liability $ 81    
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] Accrued Liabilities, Current    
Non current operating liabilities $ 8    
Minimum      
Lease accounting      
Lessee, Operating Lease, Renewal Term 3 months 18 days    
Maximum      
Lease accounting      
Lessee, Operating Lease, Renewal Term 2 years 3 months 18 days    
Accounting Standards Update 2016-02      
Lease accounting      
Operating lease liabilities     $ 186
Right of use operating assets     $ 186