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Investments in Marketable Securities - Additional Information (Details) - USD ($)
3 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Investments in marketable securities:    
Long-term marketable securities $ 0  
Fair value assets transfers between level 1, level 2 or level 3 $ 0 $ 0
Short Term Investments    
Investments in marketable securities:    
Available for sale securities maturity term less than one year