Note 12 - Employee Benefit and Retirement Plans - Portfolio by Valuation Category (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Fair Value	$ 118,693	$ 117,778
Asset Allocation	100.00%	100.00%
Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 48,813	$ 59,227
Fair Value, Inputs, Level 2 [Member]
Fair Value	69,880	58,551
Fair Value, Inputs, Level 3 [Member]
Fair Value
Cash Equivalents [Member]
Fair Value	$ 945	$ 780
Asset Allocation	1.00%	1.00%
Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 945	$ 780
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	$ 32,303	$ 21,128
Asset Allocation	27.00%	18.00%
Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value
Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	32,303	21,128
Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value
Equity Securities [Member]
Fair Value	$ 40,509	$ 28,289
Asset Allocation	34.00%	24.00%
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 38,988	$ 26,580
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	1,521	1,709
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value
Mutual and Pooled Funds [Member]
Fair Value	$ 44,936	$ 67,581
Asset Allocation	38.00%	57.00%
Mutual and Pooled Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value	$ 8,880	$ 31,867
Mutual and Pooled Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value	36,056	35,714
Mutual and Pooled Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value