Summary of Business and Significant Accounting Principles - Warranty Accrual (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Movement in Standard Product Warranty Accrual [Roll Forward] | ||
| Balance, beginning of year | $ 6,001,864 | $ 7,058,769 |
| Accrual for warranty (1) | 2,115,762 | 92,191 |
| Warranty costs incurred | (2,717,626) | (1,149,096) |
| Balance, end of year | $ 5,400,000 | $ 6,001,864 |