Annual report pursuant to Section 13 and 15(d)

Financial instruments - Fair value of assets and liabilities (Details)

v3.22.0.1
Financial instruments - Fair value of assets and liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Marketable securities:    
Marketable securities $ 219,632 $ 311,335
Recurring basis    
Marketable securities:    
Marketable securities 219,632 311,335
Recurring basis | Level 1    
Marketable securities:    
Marketable securities 214,639 305,334
Recurring basis | Level 2    
Marketable securities:    
Marketable securities 4,993 6,001
Corporate debt securities | Recurring basis    
Marketable securities:    
Marketable securities 214,639 305,334
Corporate debt securities | Recurring basis | Level 1    
Marketable securities:    
Marketable securities 214,639 305,334
Agency bond | Recurring basis    
Marketable securities:    
Marketable securities 4,993 6,001
Agency bond | Recurring basis | Level 2    
Marketable securities:    
Marketable securities $ 4,993 $ 6,001