Note 16 - Employee Benefit Plans - Fair Values of Pension Plans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Fair value of pension plan assets	$ 229,077	$ 232,249
Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	23,389	24,156
Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	205,688	208,093
Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets
Cash and Cash Equivalents [Member]
Fair value of pension plan assets	4,482	11,160
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	325	452
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	4,157	10,708
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets
Equity Securities [Member]
Fair value of pension plan assets	89,934	94,951
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	16,353	16,976
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	73,581	77,975
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets
US Government Agencies Debt Securities [Member]
Fair value of pension plan assets	14,461	11,989
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	14,461	11,989
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets
Corporate Bonds and Other Fixed Income Securities [Member]
Fair value of pension plan assets	102,105	97,691
Corporate Bonds and Other Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	6,711	6,728
Corporate Bonds and Other Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	95,394	90,963
Corporate Bonds and Other Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets
Other Debt Obligations [Member]
Fair value of pension plan assets	18,095	16,458
Other Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets
Other Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	18,095	16,458
Other Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets