Note 6 - Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Jun. 30, 2017
Accrued Expenses:
Compensation and benefits	$ 5,668		$ 9,394
Customer prepayments	1,865		1,070
Accrued sales commissions	1,776		2,274
Accrued warranty	7,095		6,876
Other accrued expenses	5,545		4,658
Total Accrued Expenses	$ 21,949	$ 24,272	$ 24,272