Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Financial Assets Measured at Fair Value on Recurring Basis (Details)

v3.20.4
Fair Value Measurements - Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Short-term investments:    
Short-term investments $ 7,233  
Fair Value, Measurements, Recurring    
Financial assets    
Total 108,662 $ 136,204
Fair Value, Measurements, Recurring | Money Market Funds    
Cash and cash equivalents:    
Money market funds 101,429 136,204
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Financial assets    
Total 101,429 136,204
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds    
Cash and cash equivalents:    
Money market funds 101,429 $ 136,204
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)    
Financial assets    
Total 7,233  
Fair Value, Measurements, Recurring | Short-term Investments - Corporate Bonds    
Short-term investments:    
Short-term investments 7,233  
Fair Value, Measurements, Recurring | Short-term Investments - Corporate Bonds | Significant Other Observable Inputs (Level 2)    
Short-term investments:    
Short-term investments $ 7,233