Note 6 - Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Accrued Expenses:
Compensation and benefits	$ 8,667	$ 9,759
Customer prepayments	840	1,061
Accrued sales commissions	2,214	2,314
Accrued warranty	6,688	7,560	$ 5,961	$ 5,069
Other accrued expenses	7,304	5,375
Total Accrued Expenses	$ 25,713	$ 26,069