Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Summary of Values of Short-term Investments (Details)

v3.20.4
Fair Value Measurements - Summary of Values of Short-term Investments (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Mutual Fund    
Schedule Of Available For Sale Securities [Line Items]    
Short-term investments, Cost $ 580 $ 5,129
Short-term investments, Unrealized gains 10 1
Short-term investments, Unrealized losses   (6)
Short-term investments, Fair value 590 $ 5,124
Certificates of Deposit    
Schedule Of Available For Sale Securities [Line Items]    
Short-term investments, Cost 4,253  
Short-term investments, Fair value $ 4,253