Note F - Economic Dependency - Substantial Net Sales to Certain Customers (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017		Mar. 31, 2018	Mar. 31, 2017
Net sales	$ 31,815	$ 25,135		$ 93,224	$ 89,761
Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member]
Net sales	20,897	11,046		60,429	43,198
Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member] | Customer 1 [Member]
Net sales	17,229	11,046		49,521	43,198
Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member] | Customer 2 [Member]
Net sales	$ 3,668		[1]	$ 10,908		[1]

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