Quarterly report pursuant to Section 13 or 15(d)

Fair value measurements (Details)

v3.19.2
Fair value measurements (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total $ 98,832 $ 136,755
Recurring basis    
Marketable securities:    
Corporate debt securities 91,831  
Agency bond 3,999  
Certificate of deposit 3,002  
Available-for-sale securities, Debt Securities, Current, Total 98,832  
Recurring basis | Level 1    
Marketable securities:    
Corporate debt securities 91,831  
Available-for-sale securities, Debt Securities, Current, Total 91,831  
Recurring basis | Level 2    
Marketable securities:    
Agency bond 3,999  
Certificate of deposit 3,002  
Available-for-sale securities, Debt Securities, Current, Total $ 7,001