Note 11 - Stock-based Compensation - Stock Options Outstanding (Details)	6 Months Ended
	Dec. 31, 2022 $ / shares shares
Outstanding, exercise prices range lower limit (in dollars per share)	$ 13.20
Outstanding, exercise prices range upper (in dollars per share)	$ 175.50
Number outstanding (in shares) | shares	37,032
Weighted average remaining contractual lifeWeighted average remaining contractual life (Year)	9 years
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 27.91
Shares Exercisable (in shares) | shares	2,671
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 151.62
Exercise Price Range 1 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)	13.20
Outstanding, exercise prices range upper (in dollars per share)	$ 19.20
Number outstanding (in shares) | shares	34,361
Weighted average remaining contractual lifeWeighted average remaining contractual life (Year)	9 years 4 months 6 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.30
Shares Exercisable (in shares) | shares	0
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0
Exercise Price Range 2 [Member]
Outstanding, exercise prices range lower limit (in dollars per share)	55.50
Outstanding, exercise prices range upper (in dollars per share)	$ 84.90
Number outstanding (in shares) | shares	431
Weighted average remaining contractual lifeWeighted average remaining contractual life (Year)	5 years 9 months 3 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 62.22
Shares Exercisable (in shares) | 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)	159.00
Outstanding, exercise prices range upper (in dollars per share)	$ 175.50
Number outstanding (in shares) | shares	2,240
Weighted average remaining contractual lifeWeighted average remaining contractual life (Year)	4 years 4 months 9 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 168.82
Shares Exercisable (in shares) | shares	2,240
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 168.82