Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Instruments (Details)

v3.21.2
Fair Value of Financial Instruments (Details) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Fair value    
Transfers between Level 2 and Level 3 $ 0 $ 0
Letter of credit collateral 1,300  
Adjusted cost    
Fair value    
Cash 7,214 6,100
Total 79,957 110,713
Fair Value    
Fair value    
Cash 7,214 6,100
Total 79,957 110,713
Cash and Cash Equivalents | Fair Value    
Fair value    
Cash 5,903 4,790
Total 78,646 109,403
Restricted Cash | Fair Value    
Fair value    
Cash 1,311 1,310
Total 1,311 1,310
Level 1 | Adjusted cost    
Fair value    
Investments 72,743 104,613
Level 1 | Fair Value    
Fair value    
Investments 72,743 104,613
Level 1 | Money market funds | Adjusted cost    
Fair value    
Investments 72,743 104,613
Level 1 | Money market funds | Fair Value    
Fair value    
Investments 72,743 104,613
Level 1 | Cash and Cash Equivalents | Fair Value    
Fair value    
Investments 72,743 104,613
Level 1 | Cash and Cash Equivalents | Money market funds | Fair Value    
Fair value    
Investments $ 72,743 $ 104,613