Note 17 - Employee Benefit Plans - Fair Values of Pension Plans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018
Fair value of pension plan assets	$ 225,870	$ 229,077
Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	9,468	23,389
Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	216,402	205,688
Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets
Cash and Cash Equivalents [Member]
Fair value of pension plan assets	7,696	4,482
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	439	325
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	7,257	4,157
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	86,415	89,934
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	1,866	16,353
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	84,549	73,581
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	9,161	14,461
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	9,161	14,461
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	97,627	102,105
Corporate Bonds and Other Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of pension plan assets	7,163	6,711
Corporate Bonds and Other Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of pension plan assets	90,464	95,394
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	24,971	18,095
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	24,971	18,095
Other Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of pension plan assets