Quarterly report pursuant to Section 13 or 15(d)

Marketable securities - Available-for-sale debt securities (Details)

v3.21.2
Marketable securities - Available-for-sale debt securities (Details)
$ in Thousands
9 Months Ended
Sep. 30, 2021
USD ($)
Debt Securities  
Marketable securities  
Amortized cost $ 197,178
Gross unrealized gains 123
Gross unrealized losses (99)
Aggregate estimated fair value 197,202
Corporate Debt Securities Maturity Period Less Than Three Months | Debt Securities  
Marketable securities  
Amortized cost 9,228
Gross unrealized gains 5
Gross unrealized losses (1)
Aggregate estimated fair value 9,232
Corporate Debt Securities Maturity Period Three Months To One Year  
Marketable securities  
Amortized cost 135,761
Gross unrealized gains 104
Gross unrealized losses (29)
Aggregate estimated fair value 135,836
Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities  
Marketable securities  
Amortized cost 52,189
Gross unrealized gains 14
Gross unrealized losses (69)
Aggregate estimated fair value $ 52,134
Minimum | Corporate Debt Securities Maturity Period One Year or Less | Debt Securities  
Marketable securities  
Available For Sale Securities Debt Maturity Period 3 months
Minimum | Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities  
Marketable securities  
Available For Sale Securities Debt Maturity Period 1 year
Maximum | Corporate Debt Securities Maturity Period Less Than Three Months | Debt Securities  
Marketable securities  
Available For Sale Securities Debt Maturity Period 3 months
Maximum | Corporate Debt Securities Maturity Period One Year or Less | Debt Securities  
Marketable securities  
Available For Sale Securities Debt Maturity Period 1 year
Maximum | Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities  
Marketable securities  
Available For Sale Securities Debt Maturity Period 2 years