Note 10 - Stockholders' Equity, Stock Options and Warrants - Summary of Transactions for Stock Options and Warrants (Details)	6 Months Ended
	Jun. 30, 2024 $ / shares shares
Number of Shares Outstanding (in shares)	1,806,589
Average Exercise Price Outstanding (in dollars per share) | $ / shares	$ 21.52
Number of Shares Issued (in shares)	0
Average Exercise Price Issued (in dollars per share) | $ / shares	$ 0
Number of Shares Forfeited (in shares)	0
Expired, warrants (in shares)	(77,285)
Average Exercise Price Expired (in dollars per share) | $ / shares	$ 33.86
Number of Shares Outstanding (in shares)	1,729,304
Average Exercise Price Outstanding (in dollars per share) | $ / shares	$ 20.97
Share-Based Payment Arrangement, Option [Member]
Number of Shares Outstanding (in shares)	47,664
Average Exercise Price Outstanding (in dollars per share) | $ / shares	$ 82.23
Number of Shares Issued (in shares)	0
Average Exercise Price Issued (in dollars per share) | $ / shares	$ 0
Number of Shares Forfeited (in shares)	(233)
Average Exercise Price Forfeited (in dollars per share) | $ / shares	$ 4.67
Expired, options (in shares)	(1,019)
Expired, options, average exercise price (in dollars per share) | $ / shares	$ 105.99
Number of Shares Outstanding (in shares)	46,412
Average Exercise Price Outstanding (in dollars per share) | $ / shares	$ 82.09