Note G - Segment Information (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Number of Reportable Segments			2
Revenues, Total	$ 36,043	$ 33,335	$ 72,575	$ 61,409
Non-US [Member]
Revenues, Total	17,494	16,909	36,380	29,789
UNITED STATES
Revenues, Total	$ 18,549	$ 16,426	$ 36,195	$ 31,620
Products Manufactured by NAIE [Member] | Non-US [Member] | Sales Revenue, Net [Member] | Product Concentration Risk [Member]
Concentration Risk, Percentage	90.00%	81.00%	80.00%	79.00%
Products Manufactured by NAIE [Member] | UNITED STATES
Revenues, Total	$ 0	$ 0	$ 0	$ 0