Note 6 - Stockholders' Equity - Summary of Activity for Stock Options and Restricted Stock (Details)	3 Months Ended
	Mar. 31, 2024 shares
Equity awards outstanding, beginning of year (in shares)	4,697,029
Granted (in shares)	0
Exercised or vested (in shares)	(2,500)
Expired or Forfeited (in shares)	0
Equity awards outstanding, end of period (in shares)	4,694,529
Restricted Stock [Member]
Equity awards outstanding, beginning of year (in shares)	9,639,068
Granted (in shares)	3,304,468
Exercised or vested (in shares)	(1,379,543)
Expired or Forfeited (in shares)	(165,514)
Equity awards outstanding, end of period (in shares)	11,398,479