Note 14 - Subsequent Events (Details Textual) - The 2017 Stock Incentive Plan [Member] - shares	1 Months Ended
	Apr. 30, 2022	Jun. 30, 2021	Jun. 30, 2020	May 31, 2019	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)		1,500,000	1,900,000	2,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		7,500,000	6,000,000		2,000,000
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)	1,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	9,000,000