Note K - Derivatives and Hedging (Details Textual) € in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2019 EUR (€)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 EUR (€)
Foreign Currency, Cash Flow Hedge Contracts, Terminations | €		€ 2.3
Gain (Loss) on Discontinuation of Foreign Currency Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	$ 132,000
Accumulated Other Comprehensive Income (Loss) Cumulative Cash Flow Hedges, Gain (Loss)			$ 957,000	$ 328,000
Deferred Tax Assets, Derivative Instruments			229,000	76,000
Prepaid Expenses and Other Current Assets [Member]
Cash Flow Hedge Derivative Instrument Assets at Fair Value			2,000,000
Other Noncurrent Assets [Member]
Cash Flow Hedge Derivative Instrument Assets at Fair Value			312,000
Reclassification out of Accumulated Other Comprehensive Income [Member]
Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months			933,000
Cash Flow Hedging [Member]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax			4,300,000	(1,400,000)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Interest Income, Effective Portion, Net			1,800,000	900,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total			1,200,000	$ 2,600,000
Foreign Exchange Contract [Member]
Derivative, Notional Amount			39,900,000		€ 32.5
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member]
Derivative, Notional Amount			$ 39,900,000		€ 32.5