Note G - Economic Dependency - Substantial Net Sales to Certain Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020		Sep. 30, 2019
Net sales	$ 39,726		$ 29,195
Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Net sales	23,958		21,549
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 1 [Member]
Net sales	23,958		14,354
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 2 [Member]
Net sales		[1]	3,970
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 3 [Member]
Net sales		[1]	$ 3,225

[1] Sales were less than 10% of the respective period's total net sales.