Note G - Segment Information (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Number of Reportable Segments			2
Revenue from Contract with Customer, Including Assessed Tax	$ 35,455	$ 31,815	$ 108,030	$ 93,224
Non-US [Member]
Revenue from Contract with Customer, Including Assessed Tax	19,233	14,580	55,613	44,369
UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 16,222	$ 17,235	$ 52,417	$ 48,855
Products Manufactured by NAIE [Member] | Non-US [Member] | Revenue Benchmark [Member] | Product Concentration Risk [Member]
Concentration Risk, Percentage	74.00%	89.00%	78.00%	82.00%
Products Manufactured by NAIE [Member] | UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 0	$ 0	$ 0	$ 0