Note 12 - Employee Benefit and Retirement Plans - Actual Asset Allocation For The Assets Within The Company's Plans (Details)	Jun. 30, 2018	Jun. 30, 2017
Asset allocation	100.00%	100.00%
Cash and Cash Equivalents [Member]
Asset allocation	1.00%	1.00%
Fixed Income Securities [Member]
Asset allocation	27.00%	18.00%
Equity Securities [Member]
Asset allocation	34.00%	24.00%
Mutual and Pooled Funds [Member]
Asset allocation	38.00%	57.00%