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Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Accounting Policies [Abstract]    
Allowance for doubtful accounts $ 1,896,038 $ 1,908,841
Provision for doubtful accounts 152,416 898,357
Allowance for doubtful accounts receivable, uncollectible $ 165,219 $ 1,346,647