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Marketable Securities (Details)
3 Months Ended
Mar. 31, 2021
USD ($)
item
Dec. 31, 2020
USD ($)
Marketable Securities    
Marketable securities $ 0 $ 0
Net pre-tax unrealized gains for marketable securities 0  
Marketable securities sold $ 0  
Number of marketable securities in an unrealized loss position | item 0