Note G - Economic Dependency - Substantial Net Sales to Certain Customers (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2019		Dec. 31, 2018
Net sales	$ 29,103		$ 36,043	$ 58,298		$ 72,575
Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Net sales	17,961		27,836	36,285		48,753
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 1 [Member]
Net sales	12,422		17,750	26,776		38,827
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 2 [Member]
Net sales	5,539		6,196	9,509		9,926
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Customer 3 [Member]
Net sales		[1]	$ 3,890		[1]		[1]

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