Note 11 - Shareholders' Equity - Stock Option Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2026	Jun. 30, 2025
Plan 1989 [Member]
Outstanding, options shares (in shares)	352,100	229,000
Outstanding, weighted average exercise price (in dollars per share)	$ 4.76	$ 6.05
Granted, options shares (in shares)	0	125,100
Granted, weighted average exercise price (in dollars per share)		$ 2.41
Exercised, options shares (in shares)	0	0
Forfeited, options shares (in shares)	(200)	(2,000)
Forfeited, weighted average exercise price (in dollars per share)		$ 6.05
Outstanding, options shares (in shares)	351,900	352,100
Outstanding, weighted average exercise price (in dollars per share)	$ 4.76	$ 4.76
Outstanding, weighted average remaining contractual life (Year)	6 years 2 months 19 days
Outstanding, aggregate intrinsic value	$ 70,000
Outstanding and exercisable, options shares (in shares)	351,900
Outstanding and exercisable, weighted average exercise price (in dollars per share)	$ 4.76
Outstanding and exercisable, weighted average remaining contractual life (Year)	6 years 2 months 19 days
Outstanding and exercisable, aggregate intrinsic value	$ 70,000
Outstanding and non-vested, options shares (in shares)	0	25,000
Non-vested options (in shares)	25,000
Non-vested, grant date fair value (in dollars per share)	$ 0.99
Non-vested, fair value	$ 25,000
Granted, grant date fair value (in dollars per share)	$ 0	$ 1.06
Granted, fair value	$ 0
Vested options (in shares)	25,000
Vested, grant date fair value (in dollars per share)	$ 0.99
Vested, fair value	$ 25,000
Forfeited non-vested options (in shares)	0
Forfeited, grant date fair value (in dollars per share)	$ 0
Forfeited, fair value	$ 0
Non-vested options (in shares)	0	25,000
Non-vested, grant date fair value (in dollars per share)	$ 0	$ 0.99
Non-vested, fair value	$ 0	$ 25,000
Non-vested, unrecognized compensation expense	$ 0
Plan 1997 [Member]
Outstanding, options shares (in shares)	2,000	2,000
Outstanding, weighted average exercise price (in dollars per share)	$ 2.74	$ 2.74
Granted, options shares (in shares)	0	0
Exercised, options shares (in shares)	0	0
Forfeited, options shares (in shares)	0	0
Outstanding, options shares (in shares)	2,000	2,000
Outstanding, weighted average exercise price (in dollars per share)	$ 2.74	$ 2.74
Outstanding, weighted average remaining contractual life (Year)	1 year 8 months 19 days
Outstanding, aggregate intrinsic value	$ 1,000
Outstanding and exercisable, options shares (in shares)	2,000
Outstanding and exercisable, weighted average exercise price (in dollars per share)	$ 2.74
Outstanding and exercisable, weighted average remaining contractual life (Year)	1 year 8 months 19 days
Outstanding and exercisable, aggregate intrinsic value	$ 1,000
Outstanding and non-vested, options shares (in shares)	0
Non-vested options (in shares)	0