Note 11 - Income Taxes (Details Textual) - USD ($)	3 Months Ended								12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent									28.00%	35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability									$ 6,300,000
Effective Income Tax Rate Reconciliation, Percent, Total									174.70%	35.60%	30.70%
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	$ 791,000	$ 2,337,000	$ 1,097,000	$ 640,000	$ (211,000)	$ (1,244,000)	$ 1,517,000	$ 1,476,000	$ 4,865,000	$ 1,538,000	$ (20,375,000)
Effective Income Tax Rate Reconciliation, Before Tax Cuts and Jobs Act, Percent									44.70%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount									$ 6,324,000	315,000
Proceeds from Equity Method Investment, Distribution										2,000,000
Deferred Tax Assets, Gross, Total	16,700,000								16,700,000
Deferred Tax Assets, Net of Valuation Allowance, Total	18,800,000								18,800,000
Deferred Tax Assets, Valuation Allowance, Total	4,999,000				2,922,000				4,999,000	2,922,000
Increase (Decrease) in Obligation, Pension Benefits											19,000,000
Unrecognized Tax Benefits, Ending Balance	10,882,000				11,588,000				10,882,000	11,588,000	10,820,000	$ 11,132,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	5,400,000				7,300,000				5,400,000	7,300,000	$ 7,000,000
Income Taxes Receivable, Noncurrent	1,820,000				$ 2,627,000				1,820,000	2,627,000
Decrease in Unrecognized Tax Benefits is Reasonably Possible	200,000								200,000
Undistributed Earnings of Foreign Subsidiaries	55,400,000								55,400,000
Foreign Earnings Repatriated									0	2,000,000
Research Tax Credit Carryforward [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	600,000								600,000
Foreign Tax Authority [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount									2,100,000	$ (2,300,000)
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	5,600,000								5,600,000
Domestic Tax Authority [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	500,000								500,000
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration	2,100,000								2,100,000
State and Local Jurisdiction [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 1,000,000								$ 1,000,000
Her Majesty's Revenue and Customs (HMRC) [Member]
Effective Income Tax Rate Reconciliation, Percent, Total										17.00%	20.00%