Note 10 - Common Stock Incentive, Stock Purchase Plans, and Other Compensation Plans - Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Outstanding, exercise prices range lower limit (in dollars per share)	$ 10.38	$ 19.20
Outstanding, exercise prices range upper (in dollars per share)	175.50	$ 175.50
Exercise Price Range 1 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)
Outstanding, exercise prices range upper (in dollars per share)
Number outstanding (in shares)	35,495
Weighted average remaining contractual life (Year)	8 years 10 months 20 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 17.99
Shares Exercisable (in shares)	9,733
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 19.20
Exercise Price Range 2 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)
Outstanding, exercise prices range upper (in dollars per share)
Number outstanding (in shares)	431
Weighted average remaining contractual life (Year)	5 years 3 months 3 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 62.22
Shares Exercisable (in shares)	431
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 62.22
Exercise Price Range 3 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)
Outstanding, exercise prices range upper (in dollars per share)
Number outstanding (in shares)	2,240
Weighted average remaining contractual life (Year)	3 years 10 months 9 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 168.82
Shares Exercisable (in shares)	2,240
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 168.82
Exercise Price Range 4 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)
Outstanding, exercise prices range upper (in dollars per share)
Number outstanding (in shares)	38,166
Weighted average remaining contractual life (Year)	8 years 6 months 18 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 27.34
Shares Exercisable (in shares)	12,404
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 46.77