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Short-term marketable securities (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]    
Amortized cost $ 224,442 $ 239,171
Gross unrealized losses (2) (3)
Fair value 224,440 239,168
Cash equivalents 162,416 158,023
Short-term marketable securities 62,024 81,145
Total 224,440 239,168
Money market funds    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost 162,416 158,023
Fair value 162,416 158,023
Commercial paper    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost 33,976 47,955
Fair value 33,976 47,955
Corporate debt securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized cost 28,050 33,193
Gross unrealized losses (2) (3)
Fair value $ 28,048 $ 33,190