Note F - Economic Dependency - Substantial Net Sales to Certain Customers (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Net sales	$ 35,455	$ 31,815	$ 108,030	$ 93,224
Customer Concentration Risk [Member] \| Revenue Benchmark [Member]
Net sales	26,025	20,897	75,616	60,429
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| Customer 1 [Member]
Net sales	18,731	17,229	58,396	49,521
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| Customer 2 [Member]
Net sales	$ 7,294	$ 3,668	$ 17,220	$ 10,908

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration