Annual report pursuant to Section 13 and 15(d)

Cash, Cash Equivalents and Marketable Securities - Additional Information (Details)

v3.20.4
Cash, Cash Equivalents and Marketable Securities - Additional Information (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
item
Dec. 31, 2019
USD ($)
item
Dec. 31, 2018
USD ($)
item
Investments Debt And Equity Securities [Abstract]      
Realized gains (losses) $ 0 $ 0 $ 0
Number of investments adjusted for other-than-temporary declines in fair value | item 0 0 0
Marketable securities $ 0 $ 49,975,000