Accounts Receivable, Net - Accounts Receivable Activity (Details) - USD ($)
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Receivables [Abstract]      
Accounts receivable $ 29,374,687 $ 17,283,107  
Less: allowance for doubtful accounts (1,534,538) (1,035,542) $ (367,044)
Accounts receivable, net $ 27,840,149 $ 16,247,565