Note 9 - Facility Closure (Details Textual) - USD ($)	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Property, Plant and Equipment, Net, Ending Balance	$ 36,679,000	$ 36,514,000
Restructuring Charges, Total			$ 988,000
Vacated Facility at Mt. Airy, North Carolina [Member]
Impairment of Long-Lived Assets to be Disposed of				$ 4,100,000
Property, Plant and Equipment, Net, Ending Balance	$ 2,200,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 100,000