Quarterly report pursuant to Section 13 or 15(d)

Fair value measurements (Details)

v3.22.1
Fair value measurements (Details) - USD ($)
Mar. 31, 2022
Dec. 31, 2021
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total $ 214,679,000 $ 219,632,000
Recurring basis    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 214,679,000  
Recurring basis | Corporate debt securities    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 167,645,000  
Recurring basis | U.S. Treasury securities    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 42,144,000  
Recurring basis | Agency bonds    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 4,890,000  
Recurring basis | Level 1    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 167,645,000  
Recurring basis | Level 1 | Corporate debt securities    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 167,645,000  
Recurring basis | Level 2    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 47,034,000  
Recurring basis | Level 2 | U.S. Treasury securities    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total 42,144,000  
Recurring basis | Level 2 | Agency bonds    
Marketable securities:    
Available-for-sale securities, Debt Securities, Current, Total $ 4,890,000