XML 59 R48.htm IDEA: XBRL DOCUMENT v3.21.1
Available-for-Sale Securities - Additional Information (Details) - USD ($)
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Investments Debt And Equity Securities [Abstract]    
Available-for-sale securities investments, gross unrealized losses $ 0  
Unrealized gain on short-term investments $ 0 $ 47,697