Income Taxes - Current and Deferred Income Tax Expense (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Abstract]      
Current income tax expense $ 183,786 $ 1,137,800 $ 463,149
Deferred income tax expense (tax benefit) 378,008 (336,463) (358,071)
Income taxes $ 561,794 $ 801,337 $ 105,078