Note H - Segment Information (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Number of Reportable Segments	2
Revenue from Contract with Customer, Including Assessed Tax	$ 39,726	$ 29,195
Non-US [Member]
Revenue from Contract with Customer, Including Assessed Tax	19,941	11,010
UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 19,785	$ 18,185
Products Manufactured by NAIE [Member] | Non-US [Member] | Product Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration Risk, Percentage	86.00%	89.00%
Products Manufactured by NAIE [Member] | UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 0	$ 0