Note 2 - Summary of Significant Accounting Policies - Stock-based Compensation Expense (Details) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
|
| Share-based Payment Arrangement, Expense | $ 1,028,399 | $ 144,100 | $ 6,989,942 | $ 2,610,412 |
| General and Administrative Expense [Member] | ||||
| Share-based Payment Arrangement, Expense | 657,148 | 77,101 | 4,837,382 | 2,149,160 |
| Selling and Marketing Expense [Member] | ||||
| Share-based Payment Arrangement, Expense | 210,739 | 27,605 | 1,127,521 | 287,680 |
| Research and Development Expense [Member] | ||||
| Share-based Payment Arrangement, Expense | $ 160,512 | $ 39,394 | $ 1,025,039 | $ 173,572 |