Note D - Other Comprehensive Loss (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Sales [Member]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	$ 211,000	$ 428,000	$ 169,000	$ 850,000
Interest Income [Member]
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	$ 464,000	$ 241,000	$ 951,000	$ 485,000

Amount before tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669686-108580

Name:	us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration