Note G - Economic Dependency - Substantial Net Sales to Certain Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Net sales	$ 25,482	$ 35,455	$ 83,780	$ 108,030
Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Net sales	16,870	26,025	53,155	75,616
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 1 [Member]
Net sales	9,271	18,731	36,047	58,396
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 2 [Member]
Net sales	$ 7,599	$ 7,294	$ 17,108	$ 17,220