Quarterly report pursuant to Section 13 or 15(d)

Fair value measurements (Details)

v3.19.3
Fair value measurements (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total $ 63,451 $ 136,755
Recurring basis    
Marketable securities:    
Corporate debt securities 59,430  
Agency bond 4,021  
Available-for-sale securities, Debt Securities, Current, Total 63,451  
Recurring basis | Level 1    
Marketable securities:    
Corporate debt securities 59,430  
Available-for-sale securities, Debt Securities, Current, Total 59,430  
Recurring basis | Level 2    
Marketable securities:    
Agency bond 4,021  
Available-for-sale securities, Debt Securities, Current, Total $ 4,021