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, 2020	Jun. 30, 2019	Jun. 30, 2018
Cost of Sales [Member]
Cost of goods sold decrease	$ 12,790	$ 710	$ 582
Selling, General and Administrative Expenses [Member]
Cost of goods sold decrease	3,963	220	212
Other Nonoperating Income (Expense) [Member]
Cost of goods sold decrease	$ (16,753)	$ (930)	$ (794)