Note 12 - Employee Benefit and Retirement Plans (Details Textual) - USD ($)		12 Months Ended
	Dec. 31, 2013	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Pension Cost (Reversal of Cost)			$ 18,600,000	$ 2,800,000	$ 2,700,000
Defined Contribution Plan, Employer Discretionary Contribution Amount			1,600,000	1,700,000	$ 1,800,000
Pension Expense (Reversal of Expense), Noncash			16,800,000
Defined Benefit Plan, Amortization of Gain (Loss)			16,800,000	300,000
Fair Value of the Company's Common Stock			$ 2,200,000	$ 4,600,000
US Domestic Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			2.73%	3.56%	4.27%
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long Term Return on Assets			5.00%	5.00%	5.00%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year			$ 7,000,000
US Domestic Plan [Member] | Forecast [Member]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long Term Return on Assets		5.00%
UK Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			1.59%	2.39%	2.80%
Defined Benefit Plan, Amortization of Gain (Loss)			$ (1,870,000)
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long Term Return on Assets			2.62%	2.98%	3.01%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year			$ 900,000
UK Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan, Plan Assets, Amount, Ending Balance			5,400,000
UK Plan [Member] | Forecast [Member]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long Term Return on Assets		2.60%
US and UK Plans Combined [Member]
Defined Benefit Plan, Plan Assets, Amount, Ending Balance			$ 123,826,000
Maximum [Member]
Fixed Contribution Toward Medical Premium for Retirees 65 and Older	$ 28.50
Maximum [Member] | Equity Securities [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			70.00%
Maximum [Member] | Company Stock [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			20.00%
Maximum [Member] | Cash and Debt Securities [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			60.00%
Minimum [Member]
Fixed Contribution Toward Medical Premium for Retirees 65 and Older	$ 23
Minimum [Member] | Equity Securities [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			40.00%
Minimum [Member] | Company Stock [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			10.00%
Minimum [Member] | Cash and Debt Securities [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			30.00%