Quarterly report pursuant to Section 13 or 15(d)

Fair value measurements (Details)

v3.20.1
Fair value measurements (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total $ 110,000 $ 39,130
Recurring basis    
Marketable securities:    
Corporate debt securities 108,002  
Treasury bills 1,998  
Available-for-sale securities, Debt Securities, Current, Total 110,000  
Recurring basis | Level 1    
Marketable securities:    
Corporate debt securities 108,002  
Available-for-sale securities, Debt Securities, Current, Total 108,002  
Recurring basis | Level 2    
Marketable securities:    
Treasury bills 1,998  
Available-for-sale securities, Debt Securities, Current, Total $ 1,998