Note 6 - Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Accrued Expenses:
Compensation and benefits	$ 5,493	$ 5,319
Customer prepayments	1,413	1,768
Accrued sales commissions	1,198	1,301
Accrued warranty	7,601	7,687
Other accrued expenses	5,468	5,136
Total Accrued Expenses	$ 21,173	$ 21,211