| Note 4 – Operating leases The following table shows the lease costs for the three and nine months ended September 30, 2019 (in thousands): 
|  |  |  |  |  |  |  |  
|  |  | Three months ended  |  | Nine months ended  |  
|  |  | September 30,  |  | September 30,  |  
|  |  | 2019 |       | 2019 |  
| Lease cost: |  |  |  |  |  |  |  
| Operating lease cost |  | $ |  989 |   | $ |  3,003 |  
| Short-term lease cost |  |   |  62 |  |   |  230 |  
|  |  | $ |  1,051 |   | $ |  3,233 |  
|  |  |  |  |  |  |  |  
|  |  |  |  |  | Nine months ended  |  
|  |  |  |  |  | September 30,  |  
|  |  |  |  |  | 2019 |  
| Other information: |  |  |  |  |  |  |  
| Operating cash flows from operating leases (in thousands) |  |  |  |  | $ |  3,176 |  
|  |  |  |  |  |  |  |  
|  |  |  |  |  | September 30,  |  
|  |  |  |  |  | 2019 |  
|  |  |  |  |  |  |  |  
| Weighted-average remaining lease term - operating leases |  |  |  |  |       7.5  years |  
| Weighted-average discount rate - operating leases |  |  |  |  | 7.2% |   The maturities of operating lease liabilities are as follows (in thousands): 
|  |  |  |  |  |  
|  |       | Operating leases |       |  
|  |  |  |  |  
| 2019 |   | $ |  1,003 |   |  
| 2020 |  |   |  4,033 |  |  
| 2021 |  |   |  4,077 |  |  
| 2022 |  |   |  4,082 |  |  
| 2023 |  |   |  3,775 |  |  
| after 2023 |  |   |  16,076 |  |  
| Total lease payments |  |  |  33,046 |  |  
| Less: Imputed interest |  |  |  (8,111) |  |  
| Present value of lease liability |  | $ |  24,935 |  |   The Company has operating leases in relation to property for office and research facilities. The maximum lease term without activation of termination options is to 2041.   |