Note 10 - Common Stock Incentive, Stock Purchase Plans, and Other Compensation Plans - Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Outstanding, exercise prices range lower limit (in dollars per share)	$ 7.47	$ 10.38
Outstanding, exercise prices range upper (in dollars per share)	175.5	$ 175.5
Exercise Price Range 1 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)	7.47
Outstanding, exercise prices range upper (in dollars per share)	$ 19.2
Number outstanding (in shares)	154,003
Weighted average remaining contractual life (Year)	8 years 3 months
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 11.83
Shares Exercisable (in shares)	21,379
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 18.55
Exercise Price Range 2 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)	55.5
Outstanding, exercise prices range upper (in dollars per share)	$ 84.9
Number outstanding (in shares)	418
Weighted average remaining contractual life (Year)	4 years 4 months 13 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 61.52
Shares Exercisable (in shares)	418
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 61.52
Exercise Price Range 3 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)	159
Outstanding, exercise prices range upper (in dollars per share)	$ 175.5
Number outstanding (in shares)	2,207
Weighted average remaining contractual life (Year)	2 years 10 months 9 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 168.97
Shares Exercisable (in shares)	2,207
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 168.97
Exercise Price Range 4 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)	7.47
Outstanding, exercise prices range upper (in dollars per share)	$ 175.5
Number outstanding (in shares)	156,628
Weighted average remaining contractual life (Year)	8 years 2 months 1 day
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.18
Shares Exercisable (in shares)	24,004
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 33.13