Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash, Uninsured Amount	$ 2.3	$ 2.7
Depreciation	$ 4.9	5.3
Standard Warranty Extended Term for Exceptions	10 years
Defined Contribution Plan, Cost	$ 2.5	2.9
Research and Development Expense	$ 3.4	$ 3.6
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares	2,156,000	1,375,000
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ 0.3
Other Expense [Member]
Gain (Loss), Foreign Currency Transaction, before Tax		$ 0.1
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	20 years
Standard Warranty Term	5 years
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life	5 years
Standard Warranty Term	1 year
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	15 years