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Property and Equipment, Net (Details) - Property, Plant and Equipment [Member] - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Property and Equipment, Net (Details) [Line Items]    
Depreciation expense $ 1.0 $ 0.9
Research and development expense 0.9 0.8
General and administrative expense $ 0.1 $ 0.1