Note 4 - Warrants (Details Textual) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Aug. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement, Expense		$ 493,000	$ 699,000	$ 1,505,000	$ 1,740,000
Equity Classified Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	150,000					100,000
Warrants and Rights Outstanding, Term (Year)	10 years					5 years
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.6					$ 0.62
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)	4 years
Class of Warrant or Right, Outstanding (in shares)		896,501		896,501			646,501
Class of Warrant or Right, Vested and Exercisable (in shares)		424,084		424,084			400,859
Share-Based Payment Arrangement, Expense		$ 50,000	$ 232,000	$ 142,000	$ 398,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount		$ 446,000		$ 446,000