Note 2 - Significant Accounting Policies - Classification of the Service Cost Compensation and Other Component of NPBC (Details) - Accounting Standards Update 2017-07 [Member] - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Cost of Sales [Member]
Net Periodic Pension Cost	$ 710	$ 582	$ 649
Pension net periodic benefit cost (NPBC)	(710)	(582)	(649)
Selling, General and Administrative Expenses [Member]
Net Periodic Pension Cost	220	212	248
Pension net periodic benefit cost (NPBC)	(220)	(212)	(248)
Other Nonoperating Income (Expense) [Member]
Net Periodic Pension Cost	930	794	897
Pension net periodic benefit cost (NPBC)	$ (930)	$ (794)	$ (897)