Note 12 - Employee Benefit and Retirement Plans - Portfolio by Valuation Category (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018
Fair Value	$ 122,033	$ 118,693
Asset Allocation	100.00%	100.00%
Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 45,809	$ 48,813
Fair Value, Inputs, Level 2 [Member]
Fair Value	76,224	69,880
Fair Value, Inputs, Level 3 [Member]
Fair Value
Cash Equivalents [Member]
Fair Value	$ 1,818	$ 945
Asset Allocation	2.00%	1.00%
Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 1,818	$ 945
Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value
Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value
Fixed Income Securities [Member]
Fair Value	$ 38,232	$ 32,303
Asset Allocation	31.00%	27.00%
Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value
Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	38,232	32,303
Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value
Equity Securities [Member]
Fair Value	$ 43,111	$ 40,509
Asset Allocation	35.00%	34.00%
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 41,629	$ 38,988
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	1,482	1,521
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value
Mutual and Pooled Funds [Member]
Fair Value	$ 38,872	$ 44,936
Asset Allocation	32.00%	38.00%
Mutual and Pooled Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 2,362	$ 8,880
Mutual and Pooled Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	36,510	36,056
Mutual and Pooled Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value