Note 8 - Per Share Data - Reconciliation of the Basic and Diluted Loss Per Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income (loss)	$ 69,450,766	$ 56,342,010	$ (7,241,147)
Less: Change in fair value of warrants	117,770	0	5,091,256
Net income (loss), adjusted for change in fair value of warrants for diluted earnings per share	$ 69,332,996	$ 56,342,010	$ (12,332,403)
Weighted average shares outstanding: basic (in shares)	75,322,194	79,259,000	81,031,254
Effect of potential common shares (in shares)	1,080,522	178,306	1,143,769
Weighted-average shares: diluted (in shares)	76,402,716	79,437,306	82,175,023
Earnings (loss) per share: basic (in dollars per share)	$ 0.92	$ 0.71	$ (0.09)
Earnings (loss) per share: diluted (in dollars per share)	$ 0.91	$ 0.71	$ (0.15)