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Revenue Recognition - Additional information (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Disaggregation of Revenue [Line Items]    
Impairment losses from CSSE contracts with customers $ 0 $ 0
Contract Liabilities $ 0 $ 6,469
Maximum [Member]    
Disaggregation of Revenue [Line Items]    
Payment term 60 days  
Minimum [Member]    
Disaggregation of Revenue [Line Items]    
Payment term 30 days