Note 12 - Employee Benefit and Retirement Plans - Actual Asset Allocation For The Assets Within The Company's Plans (Details)	Jun. 30, 2019	Jun. 30, 2018
Asset allocation	100.00%	100.00%
Cash and Cash Equivalents [Member]
Asset allocation	2.00%	1.00%
Fixed Income Securities [Member]
Asset allocation	31.00%	27.00%
Equity Securities [Member]
Asset allocation	35.00%	34.00%
Mutual and Pooled Funds [Member]
Asset allocation	32.00%	38.00%