Note H - Segment Information (Details Textual) $ in Thousands	3 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Number of Reportable Segments	2
Revenue from Contract with Customer, Including Assessed Tax	$ 38,340	$ 39,726
Non-US [Member]
Revenue from Contract with Customer, Including Assessed Tax	14,845	19,941
UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 23,495	$ 19,785
Products Manufactured by NAIE [Member] | Non-US [Member] | Product Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration Risk, Percentage	80.00%	86.00%
Products Manufactured by NAIE [Member] | UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 0	$ 0