Note O - Subsequent Events (Details Textual) € in Millions	Sep. 18, 2020 USD ($)	Jul. 30, 2020 EUR (€)	Jul. 08, 2020 EUR (€)	Jun. 30, 2020 USD ($)	Jun. 30, 2020 EUR (€)	Mar. 13, 2020 USD ($)	Jan. 08, 2020 USD ($)	Jan. 07, 2020 USD ($)
Stock Repurchase Program, Authorized Amount						$ 10,000,000	$ 9,000,000	$ 2,000,000
Subsequent Event [Member]
Stock Repurchase Program, Additional Amount Authorized	$ 2,000,000
Stock Repurchase Program, Authorized Amount	$ 12,000,000
Foreign Exchange Contract [Member]
Derivative, Notional Amount				$ 49,400,000	€ 43.5
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member]
Derivative, Notional Amount				$ 49,400,000	€ 43.5
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Subsequent Event [Member] | Designated as Hedging Instrument [Member]
Derivative, Notional Amount | €		€ 15.0	€ 17.3
Derivative, Average Forward Exchange Rate		1.1789	1.1326