Note 9 - Derivatives (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Agent Warrants In Connection With March 2020 Private Placement [Member]
Derivative Liability, Total	$ 0		$ 0		$ 135
Derivative, Gain (Loss) on Derivative, Net, Total	13	$ 1,900	135	$ 2,319
Agent Warrants Issued in Connection with May 2020 Offering [Member]
Derivative Liability, Total	0		0		333
Derivative, Gain (Loss) on Derivative, Net, Total	57	2,435	333	2,770
Agent Warrants In Connection With June 2020 Warrant [Member]
Derivative Liability, Total	8		8		$ 908
Derivative, Gain (Loss) on Derivative, Net, Total	$ 289	$ 2,973	$ 900	$ 3,172