Note 12 - Stock-based Compensation - Restricted Stock Activity (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Restricted Stock [Member]
Non Vested at December 31, 2022 and 2021 (in shares)		2,250
The 2013 Plan [Member]
Non Vested at December 31, 2022 and 2021 (in shares)	250
Vested (in shares)	(250)	(2,000)
Non Vested at March 31, 2023 and 2022 (in shares)	0	250