Note 10 - Stockholders' Equity, Stock Options and Warrants - Summary of Transactions for Stock Options and Warrants (Details)	3 Months Ended
	Mar. 31, 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)	(7,159)
Average Exercise Price Expired (in dollars per share) | $ / shares	$ 200
Number of Shares Outstanding (in shares)	1,799,430
Average Exercise Price Outstanding (in dollars per share) | $ / shares	$ 20.81
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)	(74)
Average Exercise Price Forfeited (in dollars per share) | $ / shares	$ 3.44
Expired, options (in shares)	(89)
Expired, options, average exercise price (in dollars per share) | $ / shares	$ 302.8
Number of Shares Outstanding (in shares)	47,501
Average Exercise Price Outstanding (in dollars per share) | $ / shares	$ 81.94